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N O I T A C U D E Y R A D EC O N

Y G O BIOL O GY L O E G D N A g . Domín A , e t n e S. Clem A. B. Ruiz

uez,

Building

Blocks

this is

your book

ch unit

f ea The opening pages o

Reading We read about the contributions of women in the development of the sciences, and discover some of the difficulties they had to overcome.

We speak about the different issues that will be learnt about throughout the unit.

Speaking ons. Follow the instructi game in small groups. – but don’t 3 Play a guessing of a living being in turns to think Step 1: Take it it is! discover tell anyone what it is questions to person whose turn of. Step 2: Ask the they’re thinking to think which living being turn your it’s Now guess what it is? Step 3: Can you of a living being.

Living beings Reading and listening

Lynn Margulis.

An exceptional

No Is it a protozoa?

biologist

what do you think word ‘microorganism’, and If you hear the them with danger only associate They’re of? Lots of people more than that. me they’re much illness, but for for life itself! They have existed as an example. have they and Let’s take bacteria ly varied they are incredib a very long time, bet you won’t believe environments. I purse, colonized all possible bacteria in my I carry photos of me if I tell you that of my children! , next to the photos 1938, in Chicago in born was I Margulis. y. I was My name is Lynn started universit I was only 16 I to study Biology. in the USA. When beings and wanted and help fascinated by living become a teacher ed, I decided to When I graduat that scientists do. about the work learn to of others d a great part researcher, I dedicate author As a scientific s. I was even the study of microbe my life to the of endosymbiosis. theory: the theory z, I of a revolutionary e Karlene V. Schwart with my colleagu ation of living Also, together tion to the classific protozoa proposed a modifica s. Thanks to us, kingdom five as the known beings into algae became and multicellular and unicellular sta. Kingdom Protocti woman a short, restless described me as a very My friends have and I think that’s about everything, who is curious good summary!

The audios of each unit’s content are available at www.anayaeducacion.es

Speaking

the 1 Find words in

by take over the world said ‘Life did not means? do you think she networking.’ What

once 4 Lynn Margulis combat, but by

Writing A newspaper article the work a short article about asked to write er. Do research 5 You have been school newspap logists for your of microbio information below. and include the logists do? ➜ What do microbio tions do they have? ➜ What qualifica work? ➜ Where do they logist? day like for a microbio ➜ What is a typical

text that mean…

risk a) A situation of b) Diverse c) Take control for money d) A small bag or relax e) Not able to rest her as short, restless friends describe her 2 Lynn says that describe you? three words best and curious. What

GE BANK GE BANK LANGUA LANGUA BANK GE NK GE BANK GE BA LANGUA LANGUA LANGUA BANK 27 GE BANK GE NK GE BANK GE BA LANGUA LANGUA LANGUA LANGUA BANK NK BA GE NK GE UAGE BA LANGUA LANGUA

LANG

Writing We write a variety of different styles and types of text about a subject matter in the unit. By practising different styles of writing, we will improve the writing skills we need to do well in our studies. Focus on English Do you think Biology and Geology and English have anything in common? Discover how language, biology and geology are linked so you can learn them together.

CONTENT DEVELOPMENT 9

Create

Unit 3

THE CONSERVATION OF ECOSYSTEMS

9.1 We use ecosystems As consumers, we humans use resources from ecosystems to meet our needs: we breath air and drink water, we mine rocks, we cultivate and live off the land, and we generate energy from the environment. Above all we take advantage of the planet’s biodiversity.

Biodiversity as a resource Biodiversity, or biological diversity, is the variety or richness of living beings on our planet. Biodiversity is the Earth’s most valuable resource. It is essential for life to develop on the planet and for ecosystems to maintain their balance. But it also provides us with useful resources. For example:

➜ Food. We eat living beings and their produce. Today, we grow the plants and rear the animals we need, but we still catch food, particularly in marine ecosystems, through fishing.

5.2 Alternation of generations in seedless plants

Seedless plants, like mosses and ferns, have a life cycle in which two generations alternate:

➜ The sporophyte generation, which contains the sporangia, where spores form for asexual reproduction;

➜ The gametophyte generation, which contains the gametangia, where gametes form for sexual reproduction. In mosses, the part of the plant you can see is the gametophyte. After fertilisation, the sporophyte develops as a filament that ends in a capsule, the sporangium, which contains spores. In ferns, the part of the plant you can see is the sporophyte. This contains the sporangia (clustered together into sori), where spores form.

Visual arts

virtual herbarium. REATE A Herbaria are collections of dried plants that botanists use for study and research. You are going to prepare a herbarium without picking plants from their environment.

The life cycle of a moss 2 The male gamete reaches

the female gamete due to rainfall, and fertilises it to form the zygote.

➜ Medicines. Many organisms contain or produce

3 The zygote develops into

the sporophyte. This grows a capsule inside which spores form.

substances that we use to make medicines, like antibiotics.

➜ Raw materials. We get materials like wood and fibres from plants. We get leather and wool from animals.

Zygote

➜ Energy. In some places, firewood is still the primary

Male reproductive organ

fuel and animals are the main source of power for transport or physical labour.

➜ Well-being. Biodiversity has aesthetic, cultural and

Female reproductive organ

Young sporophyte

educational value. Because of all this, biodiversity is considered to be an indicator of a country’s wealth.

ocus on English Over can be used with the meaning of higher than or above in position, number or authority. Therefore, overexploitation refers to exploiting a renewable resource to the point of using it up completely. There are many words that begin with the prefix over- such as overbooking, overcrowded, overdone or overpriced. What do they mean?

Working with pictures Develop your abilities to observe and interpret pictures.

Understand, think, search... 1 Why is biodiversity considered to be an indicator of

Working with pictures 1

a country’s wealth?

Look at the photos and compare how resources from biodiversity are being used in each scene. What similarities and differences can you see?

Pencils in the middle. In groups, write a list of everything you see around you that comes from living beings. Could you live without these items?

Spores

Gametophyte

4 The capsule on the sporophyte

1 Male and female reproductive organs form in the gametophyte, and produce male and female gametes respectively.

releases spores, which fall to the ground and germinate to form a gametophyte.

Young gametophyte

Mature sporophyte

Understand, think, search... 4 Why are mosses and ferns said to have a life cycle

Write a short explanation of how alternation of generations occurs in ferns.

involving alternation of generations?

5 What is the gametophyte of seedless plants? And the sporophyte? What is the structure that produces spores?

Do some research to answer the following question: in mosses, how are male gametes dispersed to the female reproductive organ?

156

The icons included with some activities indicate the keys to the project.

Understand, think, search...

In this section we create a crosscurricular project that joins Biology and Geology with other subjects. Have you ever thought that Biology and Geology could be joined with visual arts to improve your creative skills? Visual aids to support your understanding of the contents.

Activities that expand on the contents and inspire curiosity about scientific investigation.

KEY

PROJECT

SDG

SDG Commitment Discover the Sustainable Development Goals and be an active part of our commitment to make a more equal and liveable world.

Developing thinking Work on strategies for thinking: reflect on the content you are learning, generate ideas, organise them, debate them, explain them…

Cooperative learning Get involved in your learning and participate in the group’s learning; you will find that cooperating improves performance and harmony in the class.

Emotional education Get to know yourself; identify the situations that bring up complicated emotions and manage them with constructive, self-affirming experiences.

Research Project This book contains three research projects.

REVIEW AND PRACTISE They are divided into steps that you will find at the end of each unit.

from this resources to choose Remember o. your portfoli

UNIT 1

ect

research proj

unit for

Unit 7

TISE

review and PRAC

researching Seed germination

Organising your ideas 1

Project presentation

Background research and project planning

STEP 1

Third inner planet, ? km from the Sun

Your teacher will divide the class into groups of three or four students. Once you have been placed in a group, discuss the project and how you intend to carry it out. Divide the work between all members of the group.

Once the seed has germinated, a seedling emerges. As it continues to grow, it is affected by other environmental factors, such as the concentration of salt in the soil (salinity) and the amount of liquid water present.

of?

Dicotyledon

➜ Step 2 (in unit 2). Formulating a hypothesis, then planning and

c) They are celestial bodies that orbit the Sun in belts.

b) Why does it occur? c) Is this phenomenon equally visible everywhere on Earth? Why?

5 What phenomenon can you see in the photos? Why

d) They are small spheres that orbit the Sun.

10 Why do we always see the same side of the Moon?

does it occur? How often does it occur?

11 What is the difference between: a) A solar eclipse and a lunar eclipse?

• What bodies make up the Solar System?

parts.

➜ What differences can you find between the different types of seeds?

• In order of distance from the Sun, what are the

You could look at lentils, beans, chickpeas and corn, for example. How many cotyledons do the seeds you have chosen have? They should have one or two.

planets of the Solar System? Which are inner planets and which are outer planets?

b) A spring tide and a neap tide? c) A planet and a planetoid?

Moving forward

• What are lunar phases? Can you name them?

12 The closest star to the Solar System is in the Alpha

• How does the Earth move? What are the effects

Centauri star system, located 4.3 light years away from us. Calculate the distance between us and Alpha Centauri in kilometres and in astronomical units.

of its movements?

• What is an eclipse, and what types are there?

➜ What is salinity? Where does the salt found in the liquid water used

Once you have completed these steps, you should write a scientific article in order to present and explain your findings to the class.

for plants come from? How might salinity affect plants?

What are tides, and what types are there? anayaeducacion.es Go to ´Science workshop: how to navigate using celestial bodies´ in your resource bank.

182

Specific curriculum content for Andalucía is included at the end of each term.

➜ The geographical features of the region; ➜ The fact that foreign species (species from other

A Alternation of generations A system of reproduction where one phase involves sexual reproduction by gametes and the other phase involves asexual reproduction by spores.

Kingdom Monera Unicellular prokaryotic organisms that can be autotrophic or heterotrophic. Bacteria are the most representative organisms of this kingdom.

The blue Spanish fir is the most important fir tree of our Community. It grows in Sierra de las Nieves, Sierra Bermeja and Sierra de Grazalema.

Kingdom Protoctista A group of non-tissue-forming eukaryotic organisms that can be multicellular or unicellular. Some use autotrophic nutrition (algae) and others use heterotrophic nutrition (protozoa).

Sporangia Reproductive organs containing spores. Spores

and

The coastal landscape between the Strait of Gibraltar and Almuñécar alternates between fine-sand beaches and mountains and small cliffs.

Rüppell’s vulture is native to Africa but is increasingly common in Andalucía as a result of climate change.

Africa’s

These include: (in other words, that only exist in the region)

➜ 175 species that are endemic to the Iberian Peninsula.

Budding A type of asexual reproduction where two daughter cells form, with one developing as a bud on the other. Flamingos are migratory birds that spend the winter sheltering in wetlands, like the Fuente de Piedra lake in Malaga.

Fragmentation A type of asexual reproduction where a new individual forms from a fragment of another.

H Hyphae Filamentous structures formed of groups of cells that make up the body of a multicellular fungus.

Bud

M Mould A type of multicellular fungus in which the mycelium has a cottony appearance. Mycelium The body of a multicellular fungus formed by strands of hyphae.

In the most easterly part of the autonomous community, the Betica mountains extend almost as far as the sea and there are more cliffs.

1 Dwarf fan palms are very common along all of

3 The regions of La Janda and Campo de Gibraltar

Andalucía’s coastline, especially in Cabo de Gata in Almería. Which part of this plant is edible?

see the highest numbers of migratory birds passing through. What municipalities are in these regions? Why do you think birds choose this area? Can you name some species that inhabit these parts?

2 The bird population is higher in our autonomous community than it is in most of Europe. Why do you think this is?

anayaeducacion.es Go to ‘Andalusian species’ in your resource bank.

Enterprising culture Trust in your skills and knowledge, develop creativity, adapt to changing situations and have a proactive and responsible attitude.

Symbiosis A mutually beneficial relationship between two individuals of different species.

Y Yeast Unicellular fungi.

Understand, think, search...

This great geographical diversity results in different microclimates. Because of that, our autonomous community has a variety of fauna and some of the most unique flora in Europe.

➜ Around 65 Species that are endemic to the region

Flagellum

The red-knobbed coot lives in a very small number of lakes in the provinces of Cádiz and Malaga, and occasionally in Doñana.

➜ Our proximity to Africa, which makes us a bridge biodiversity

Pseudopods

S Saprophyte An organism that feeds on remains of decaying organic matter.

Sporangia

➜ The Guadalquivir valley, which forms a sediment-

between Europe’s biodiversity.

P Parasite An organism that lives off another organism of a different species, harming it but not killing it.

Cilia

F Flagellum A long appendage extending from the plasma membrane of some cells, which they use like a whip in order to move.

mountains: their different geological features create varying soil types across the autonomous community;

bordering the Atlantic Ocean, a Mediterranean area near the Strait of Gibraltar where cliffs start to appear, and another Mediterranean area where the Betica mountains go down to the Mediterranean sea, resulting in huge cliffs;

183

Pseudopods Foot-like projections of the cytoplasm in some cells, which enable the cell to move or capture food.

➜ The presence of Sierra Morena and the Betica

➜ A varied coastline with a low and sandy strip

In groups, design a sustainable urban lighting system that reduces the impact of light pollution.

The Atlantic beaches along Huelva and Cádiz are low and sandy.

Andalucía’s geographical features

Cilia Small motile filaments on the surface of some protozoa that beat to enable movement.

Binary fission A type of asexual reproduction in unicellular organisms where the parent cell divides into two identical daughter cells.

areas) have settled here;

➜ The fact that Andalucía is the last refuge of some

The following factors influence Andalucía’s geography:

anayaeducacion.es Go to ‘Key concepts’ and ‘Learn by playing’ in your resource bank.

Glossary

The dwarf fan palm is the only palm tree that is native to Europe, in other words, that originated in Europe. Their soft cores (hearts) are edible and they are industrially cultivated for consumption, although nowadays consumption is regulated by law.

Andalucía’s biodiversity is due to a combination of several factors:

b) How does light pollution affect living beings?

Unit 2

I n a n d a lu C Í a

Some unique species that live in Andalucía

What makes Andalucía so biodiverse?

a) Why are stars easier to see outside cities?

We learn the relevant terms within the unit with a clear definition.

glossary

biodiversit y .............. ............................................

rich plain that has allowed farming to develop. At the mouth of the Guadalquivir we find the Doñana marshes, a major resting place for many migratory birds;

we must make cities and human settlements inclusive, safe, resilient and sustainable. An estimated 55 % of the world’s population lives in cities, and that figure is expected to increase to 68 % by the year 2050. Light pollution is also expected to increase, since cities are the primary cause of it. Look at the information about Goal 11.3 (at anayaeducacion.es) and answer the following questions.

b) They are celestial bodies that orbit planets.

are there?

➜ What are seeds? Draw a diagram of a seed and label the different

➜ What factors can influence germination?

➜ Step 3 (in unit 3). Analysing your results and coming to a conclusion.

➜ The way in which we manage our natural environment.

c) Stars never die, they fade away.

a) They are small celestial bodies formed of ice and rock. They have a tail. a) What phenomenon is this?

• What are stars? Focusing on our Sun, what types

Use your research to answer the questions:

➜ What conditions do you need to ensure that your seeds thrive?

conducting the experiment in order to prove your theory.

species;

16 According to Sustainable Development Goal 11,

what types are there? Monocotyledon

and project planning in order to plan how you will conduct your experiment.

The Andalusian coast

Black holes aren’t actually holes. You’ve probably heard of them in science fiction books or films. Search for information to find out what they are, and write a science fiction story that includes a description of their origin and characteristics.

• What are galaxies? Focusing on the Milky Way,

➜ Step 1 (in this unit). Doing the necessary background research

Andalucía is one of the most biodiverse regions in the whole of Europe, both because of the number of different species that live there and because of the many species that are unique to it.

distant space is to look back in time.’

Sustainable Development Goals

following statements refer to:

• How did the universe originate? What is it formed

14 Explain the following sentence: ‘To look into

statements:

b) Nuclear fusion reactions that give off large amounts of energy take place on the surface of stars.

d) Our star, the Sun, revolves but does not rotate.

Write your own unit summary based on the outline below:

• What are the similarities and differences between

Do some research on the nuclear reactions that take place inside the Sun. What will happen when these reactions stop?

a) We only characterise stars by their colour and brightness.

9 Decide what type of celestial body each of the Summarising

universe?

Methodology

7 Why do stars emit their own heat and light? 8 Identify and correct the errors in the following

Solid planet formed of ?

the heliocentric model and the geocentric model of the universe? Why are neither accepted today?

This experiment consists of three different steps:

the light year or to the astronomical unit: a) It is the distance that light travels in 1 year.

d) It is the average distance between the Earth and the Sun.

4 Look at the picture below and answer the questions:

• What units do we use to measure distances in the

Steps

6 Decide whether the following statements refer to

c) It is equivalent to 10 000 000 million kilometres.

Mass ?

Surrounded by ? and covered by ?

b) It is equivalent to 150 million kilometres.

Divided ?

Mass ?

Finding and analysing information

During this experiment, you will observe how environmental factors affect the germination of different types of seeds. You will also observe how this impacts subsequent plant growth. At the end of the experiment, you will create a scientific article to present your findings and conclusions.

Based on the following picture of the Solar System, write down all the bodies it consists of and their main characteristics.

The Earth

Each group will select two different types of seeds for the experiment. All of the groups should choose different seeds. This will make it possible for the class as a whole to study more seeds of different plant types.

Before starting any kind of experiment, you must research the topic that you are going to study. You should try to gather as much information as possible and make sure you consult a variety of different sources. It is also important to check that the sources you use are reliable. Don’t forget to cite your sources when you present your results!

Project objective

Sphere flattened at the poles, with a diameter of ?

Divided ?

Before you begin, remember to consult the ‘Steps to be followed in group work’ resource, which is available at anayaeducacion.es.

Applying your knowledge

Interpreting pictures

Attribute web. In your notebook, complete the empty spaces of the wheel of attributes below. Learn how to draw a wheel of attributes using the resource available at anayaeducacion.es.

Planning your work

In order for germination to occur, seeds need the right amount of light, correct temperature and an appropriate amount of moisture. Each species has its own specific requirements.

SDG. Reflect and suggest actions that could help achieve the goal mentioned in each unit.

Applying your knowledge

C Chlorophyll A green substance that captures energy from the Sun and allows photosynthesis to take place. We find it in plants, some algae and some bacteria.

Mycelium

Kingdom Fungi A group of unicellular or multicellular living beings that are formed of eukaryotic cells, have no real tissues and use heterotrophic nutrition.

Academic and professional

ICT

orientation

Evaluation

Linguistic Plan

Learn how to obtain information, select it and apply it; to plan, manage and work on projects; and to collaborate online in an ethical and safe manner.

Evaluate your personal skills, discover and awaken your calling, train yourself to make decisions and learn to choose between different options.

Discover different strategies to analyse what you have learnt and how you learnt it; train yourself to take responsibility or overcome difficulties.

Use your communication skills in the different types of text that you will see. Language is always present, communicate!

The resource bank is LIKE THIS www.anayaeducacion.es A space with resources, techniques and activities, designed to strengthen your knowledge. Access the resource bank by registering at anayaeducacion.es. You just need to have an email, the code indicated on the first page of this book and the permission of a parent or a legal guardian. More about the keys

Resources related to

THE keys of the project SDG

SDG Commitment, with microvideos that will help you know what are the targets for reaching the Sustainable Development Goals worked on in this project.

Linguistic Plan, with infographics that will give you models to work with the four linguistic skills using different types of texts (descriptive, narrative, explanatory, etc.).

Developing thinking, where explanations are included on how to apply the different strategies for thinking proposed in the project.

Cooperative learning, which includes the description of the cooperative learning techniques proposed in the project. Emotional education, with resources to support you with overcoming worries in different situations in your learning process (beginning of the school year, taking a test, etc.).

ICT, by using data sheets that will reinforce your healthy, correct and safe use of information and communication technologies.

Academic and professional orientation, with information on different professions linked to the subject content.

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Evaluation, which includes resources for your portfolio, as well as rubrics and targets that will facilitate your self-evaluation.

NOTEWORTHY

resources in the material Language Bank Autonomous content Scientific readings Sicence workshop Key concepts Learn by playing Videos

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Resources classified

by unit

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All the resources are classified so that you can easily locate the ones related with each section of your unit.

Course Contents THE SCIENTIFIC METHOD

Page 8

1. The scientific method ........................................................ 10 2. Research in the laboratory ............................................... 12 3. Research in the natural environment ........................... 16 4. Searching for information ................................................ 20 Review and practise ............................................................... 22 Glossary ....................................................................................... 24

Plants

Page 64

1. Kingdom plantae ................................................................. 66 2. The classification of plants .............................................. 68 3. Vital functions in plants: nutrition ................................. 72 4. Vital functions in plants: interaction ............................. 74 5. Vital functions in plants: reproduction ........................... 76 6. Plants, humans and the environment .......................... 80 Research project STEP Researching seed germination ............................................ 82 Review and practise ............................................................... 84 Glossary ....................................................................................... 86

LIVING BEINGS

Page 26

1. Our planet and conditions for life on Earth ............... 28 2. What is life on Earth made of? ....................................... 30 3. Cells: the building blocks of life ..................................... 32 4. Vital functions ....................................................................... 36 5. The classification of living beings ................................. 38 6. The five kingdoms ............................................................... 40 Research project STEP Researching seed germination ............................................ 42 Review and practise ............................................................... 44 Glossary ....................................................................................... 46

Biodiversity in Andalucía (I)

Animals: Vital functions

Page 88

1. Kingdom animalia ............................................................... 90 2. Nutrition in animals: obtaining nutrients ................... 92 3. Nutrition in animals: respiration .................................... 94 4. Nutrition in animals: circulation and excretion ........ 96 5. Interaction in animals: the sense organs ................... 98 6. Interaction in animals: coordination ............................ 100 7. Interaction in animals: effectors .................................... 101 8. Reproduction in animals .................................................. 102 Research project STEP Studying an ecosystem and its biodiversity .................. 106 Review and practise .............................................................. 108 Glossary ....................................................................................... 110

Monera, protoctista and fungi

1. Kingdom 2. Kingdom 3. Kingdom 4. Kingdom

Page 48

monera ................................................................. 5 0 protoctista: Protozoa ...................................... 5 2 protoctista: Algae............................................. 54 fungi ...................................................................... 5 6

Research project STEP Researching seed germination ............................................ 5 8 Review and practise ............................................................... 60 Glossary ....................................................................................... 62

ANIMALS: CLASSIFICATION

Page 114

1. Porifera and cnidaria ........................................................ 116 2. Worms: platyhelminths, nematodes and annelids ........................................................................ 117 3. Molluscs ................................................................................. 118 4. Echinoderms ....................................................................... 119 5. Arthropods ........................................................................... 120 6. Fish .......................................................................................... 122 7. Amphibians .......................................................................... 123 8. Reptiles .................................................................................. 124 9. Birds ........................................................................................ 125 10. Mammals ............................................................................... 126 11. Animals, humans and the environment .................... 128 Research project STEP Studying an ecosystem and its biodiversity .................. 130 Review and practise ............................................................... 132 Glossary ...................................................................................... 134

ECOSYSTEMS

Page 136

1. What is an ecosystem? ..................................................... 2. Abiotic factors ..................................................................... 3. Biotic interactions .............................................................. 4. Trophic levels ........................................................................ 5. Food chains and webs ...................................................... 6. Terrestrial ecosystems: biomes ..................................... 7. Aquatic ecosystems ........................................................... 8. Soil as an ecosystem ......................................................... 9. The conservation of ecosystems ..................................

1 38 1 40 1 42 1 44 1 46 1 48 1 52 1 54 1 56

Research project STEP Studying an ecosystem and its biodiversity .................. 1 60 Review and practise .............................................................. 162

THE ATMOSPHERE AND THE HYDROSPHERE

Page 186

1. The Earth’s atmosphere .................................................... 188 2. The atmosphere and living beings ................................ 190 3. Air pollution and its consequences .............................. 192 4. Water and living beings .................................................... 196 5. Where is the Earth’s water? ............................................. 198 6. The water cycle .................................................................... 199 7. Uses of water and sustainable water management ........................................................................ 200 Research project STEP Researching air pollution ...................................................... 204 Review and practise ............................................................. 206 Glossary ...................................................................................... 208

Glossary ....................................................................................... 164

Biodiversity in Andalusía (II) Ecosystems in Andalucía

THE UNIVERSE

Page 166

The geosphere: rocks and minerals

Page 210

1. The universe .......................................................................... 168 2. Galaxies and stars ............................................................... 170 3. The Solar System ................................................................ 172 4. The Earth and the Moon .................................................. 174 5. The Earth’s movements .................................................... 176 6. Eclipses and tides ............................................................... 178

1. The Earth and its geosphere ........................................... 212 2. Components of the geosphere: minerals ................... 214 3. Components of the geosphere: rocks ......................... 218 4. Geosphere resources and humans ................................ 220

Research project STEP 1 Researching air pollution ...................................................... 180

Review and practise ............................................................... 226

Review and practise ............................................................... 182

Research project STEP Researching air pollution ....................................................... 224 Glossary ....................................................................................... 228

Glossary ...................................................................................... 184

Water resources in Andalucía

Living beings Reading and listening

Lynn Margulis. An exceptional biologist If you hear the word ‘microorganism’, what do you think of? Lots of people only associate them with danger and illness, but for me they’re much more than that. They’re life itself! Let’s take bacteria as an example. They have existed for a very long time, they are incredibly varied and they have colonized all possible environments. I bet you won’t believe me if I tell you that I carry photos of bacteria in my purse, next to the photos of my children! My name is Lynn Margulis. I was born in 1938, in Chicago, in the USA. When I was only 16 I started university. I was fascinated by living beings and wanted to study Biology. When I graduated, I decided to become a teacher and help others to learn about the work that scientists do. As a scientific researcher, I dedicated a great part of my life to the study of microbes. I was even the author of a revolutionary theory: the theory of endosymbiosis. Also, together with my colleague Karlene V. Schwartz, I proposed a modification to the classification of living beings into the five kingdoms. Thanks to us, protozoa and unicellular and multicellular algae became known as Kingdom Protoctista. My friends have described me as a short, restless woman who is curious about everything, and I think that’s a very good summary!

1 Find words in the text that mean… a) A situation of risk b) Diverse c) Take control d) A small bag for money e) Not able to rest or relax

2 Lynn says that her friends describe her as short, restless and curious. What three words best describe you?

Speaking

3 Play a guessing game in small groups. Follow the instructions. Step 1: Take it in turns to think of a living being – but don’t tell anyone what it is! Step 2: Ask the person whose turn it is questions to discover which living being they’re thinking of. Step 3: Can you guess what it is? Now it’s your turn to think of a living being.

Is it a protozoa?

4 Lynn Margulis once said ‘Life did not take over the world by combat, but by networking.’ What do you think she means?

Writing A newspaper article

5 You have been asked to write a short article about the work of microbiologists for your school newspaper. Do research and include the information below.

➜ What do microbiologists do? ➜ What qualifications do they have? ➜ Where do they work? ➜ What is a typical day like for a microbiologist?

NK E BANK A B E G A ANGU LANGUAG L ANK ANK GE BANK B B E E G G A A U U GUA K LANG ANG N L A L AN GE BANK 27 ANK GE BANK B B E E G G A A U U G A LAN LANG LANGUA LANGU

1 OUR PLANET AND CONDITIONS FOR LIFE ON EARTH

There are eight planets in our Solar System and we live on the planet Earth. The Earth orbits the Sun, which is one of the hundreds of thousands of millions of stars that form our galaxy, known as the Milky Way.

1.1 The Earth The Earth is a solid planet mainly made up of rocks. It is surrounded by a layer of gases and also has liquid water on its surface. It is the only planet in our Solar System that contains life. The four things mentioned above, that is, rocks, gases, liquid water and life, correspond to the Earth’s four different layers or ‘spheres’ and how they interact with each other.

The Earth is divided into four layers or ‘spheres’ that constantly interact with each other: the biosphere, the atmosphere, the hydrosphere and the geosphere.

The Earth’s different layers

The atmosphere A layer of gases surrounding the Earth

The hydrosphere

The biosphere

All of the liquid water on the Earth

All the living beings inhabiting the Earth

The geosphere The solid base made up of rocks and minerals

Unit 1

1.2 The conditions neccesary for life The Earth is the only planet in our Solar System that contains living beings. Life on Earth is able to exist only because of the conditions found here, which is not the case for any other planet near to ours.

➜ The distance between the Earth and the Sun is ideal for life to exist. Solar radiation produces light and heat. If we were closer to the Sun, there would be too much solar radiation. If we were further away, there would be too little.

➜ The atmosphere protects the Earth from some solar radiation that is harmful to life and it also helps to keep our planet warm. It also contains two gases, namely oxygen and carbon dioxide, which we need for respiration and which plants need for photosynthesis.

F ocu s on Eng lish Bio- is a combining form which literally means life. It comes from the Greek bíos (life). Biology, biodiversity and biosphere are compound words which use this combining form. This will help you to understand better what they mean. Bio- is used to indicate a human life or career: biography, biopic.

➜ The average temperature on Earth is 15°C, which makes it possible for liquid water to exist. Liquid water is essential for both living beings and their environments. The Sun’s energy makes it possible for liquid water to change states (for example, liquid to solid or liquid to water vapour). It causes liquid water to evaporate, which is then recycled in the clouds and, as a result of gravity, eventually falls back down to the Earth. This process occurs constantly and is known as the water cycle.

Life could no longer exist

All the liquid water would evaporate from our atmosphere and hydrosphere.

➜ The Earth’s climate is also less hostile because we have seasons and there is a quick change between day and night.

Understand, think, search... 1 Why do we say that the Earth’s four layers or spheres interact with each other?

Look up the prefixes bio-, hydro-, atmos- and geo- in the dictionary and write a word beginning with each one.

3 The atmosphere is the gaseous mass surrounding the Earth and is made up of many different gases. Find out which gases make it up. Which of them are essential for life? Why?

The What If...? Life is possible on Earth thanks to our planet’s location in relation to the Sun. However, life on our planet could be affected if the Earth were to move closer to or further away from the Sun, or if there were a change in atmospheric conditions. On the right is a chart visually organising ideas about what would happen if the Earth were closer to the Sun. Look at it carefully and apply this thinking tool to each of the following cases (go to the resource bank at anayaeducacion.es to learn how to apply this thinking tool). a) What would happen if the Earth moved slightly further away from the Sun? b) What would happen if there was a change in the atmosphere’s composition, for example if its carbon dioxide concentration increased?

There would be widespread drought.

The poles would melt.

The temperature would increase.

What would happen if the Earth was closer to the Sun?

The Earth would orbit closer to the Sun.

Gravity on the Earth would change.

A different orbit would change the seasons.

Life could no longer exist. 29

2 WHAT IS LIFE ON EARTH MADE OF?

As you already know, the biosphere consists of all the living beings that inhabit the Earth. All living beings have three things in common which enable us to distinguish them from non-living beings:

➜ All living beings are made up of the same kind of substances: organic and inorganic substances.

➜ They are all made up of similar units: cells. ➜ They perform three vital functions: nutrition, interaction and reproduction.

2.1 The chemical composition of life Everything in the universe is made up of tiny units called atoms.

Inorganic substances

Oxygen and hydrogen are examples of different kinds of atoms. Atoms join together to form different substances. For example, two hydrogen atoms join together with one oxygen atom and form a water molecule.

Oxygen atom

Living beings are made up of two kinds of substances:

➜ Inorganic substances, which can be found in both living and

Hydrogen atoms

non-living beings. Examples include liquid water and mineral salts.

Water molecules are made up of two hydrogen atoms and one oxygen atom.

Chlorine atom

Sodium atom

➜ Organic substances or biomolecules, which are exclusively found in living beings. Examples include carbohydrates, lipids, proteins and nucleic acids.

2.2 Inorganic substances Liquid water Liquid water is an essential component for living beings. In fact, 70% of living matter is made up of liquid water. Liquid water also plays a key role in most transformations that happen inside cells.

Mineral salts Mineral salts help to regulate many vital processes. They also have a structural function in the skeletons of living beings.

Sodium chloride, commonly known as salt, is made up of chlorine and sodium atoms. In its solid state, this salt forms a crystalline structure, which means it is organised like in the picture. However, when it is in an aqueous solution, the bonds between the ions (positive and negative atoms) dissociate.

Understand, think, search... 1 Name the three things that all living beings have in common. 2 What are the main components of all living beings? 3 Explain why carbohydrates, lipids, proteins and nucleic acids are called biomolecules.

Unit 1

2.3 Organic substances

Organic substances

Carbohydrates Carbohydrates are a type of biomolecule that provide cells with energy. They also form part of some cell structures, such as the cell wall, which you will study in this unit.

Lipids Lipids are molecules that contain a lot of energy. Cells use them to store energy. They also provide heat insulation and form part of certain cell structures, such as the plasma membrane, which you will study in this unit.

Glucose molecule (carbohydrate)

Proteins Living beings contain billions of protein molecules. Proteins are essential for many different functions. For example, they help us to contract our muscles.

Fatty acid molecule (lipid)

Nucleic acids Nucleic acids are relatively large molecules. In fact, DNA (deoxyribonucleic acid), which contains vital information that organisms need to function, is an example of a nucleic acid.

Understand, think, search... 4 Look at the information about the chemical composition of a human being. a) Calculate the percentages of organic substances and inorganic substances in this living being.

Protein macromolecule

b) Which biomolecules provide living beings with energy? Lipids 9 %

Carbohydrates 4 % Mineral salts 1 %

Protein 16 % Water 70 %

Nucleic acid macromolecule

Working with pictures a) Look at the glucose and fatty acid molecules in the picture. The black spheres represent carbon, while the white ones represent hydrogen and the red ones represent oxygen. How many carbon, hydrogen and oxygen molecules are there in each of these substances? b)

Thinking hats. Proteins and nucleic acids are macromolecules. In other words, they are molecules with very complex structures. Do some research to find out about the structure of these molecules. What are they made up of?

3 CELLS: THE BUILDING BLOCKS OF LIFE

3.1 What are cells like? Biomolecules group together to form more complex structures inside cells. These structures enable cells to perform their functions. In general, cells are microscopic in size, so we cannot see them with the naked eye. As a result, we could not study them until microscopes were invented and further developed. All cells are made up of the following fundamental components:

➜ The plasma membrane, which is a thin layer that protects the cell. It regulates the exchange of substances coming in and out of the cell from the surrounding environment.

➜ The cytoplasm, which is a kind of liquid that fills the inside of the cell. It contains many different substances and cell components.

➜ Genetic material, which is made up of DNA fibres. This contains all the information needed to control cell functions and can be passed on to the next generation of daughter cells during reproduction.

Prokaryotic cell

➜ Organelles, which are small structures that specialise in performing specific functions. Not all organelles are found in all the different types of cells.

Cell wall

3.2 Types of cells

Plasma membrane

There are two different types of cells. These are prokaryotic and eukaryotic cells.

Genetic material (DNA)

Prokaryotic cells Prokaryotic cells do not have a nucleus. As a result, the DNA found in these cells is contained in the cytoplasm. They have a cell wall and just one type of organelle known as a ribosome, whose task is to synthesise proteins. They may have flagella, which are a kind of filament that help the cell to move.

Understand, think, search... 1 How do we classify cells as prokaryotic or eukaryotic? Cytoplasm

2 Which cellular structures are being defined in the phrases below? a) This contains mainly water and dissolved substances. b) This structure forms a boundary around the cell.

Ribosomes

c) This controls cellular activity.

3 Flagella

Using a search engine, look for three images of prokaryotic cells taken under an electron microscope. a) Draw the shape of them in your notebook and label the structures you identify. b) Which structures have you identified? Which are present in all the prokaryotic cells you found? Which are not present? What is the function of each structure?

anayaeducacion.es Go to ‘Cell theory’ in your resource bank.

Unit 1

Eukaryotic cells

Understand, think, search...

Eukaryotic cells are more complex than prokaryotic cells. The DNA they contain is surrounded by a membrane, which forms the nucleus. They have a plasma membrane and cytoplasm, which contain many different types of organelles, as well as ribosomes. Mitochondria are an example of this type of organelle. They are specialised in generating energy.

The mirror. Look at the images of the eukaryotic plant cell and the eukaryotic animal cell, then copy the following chart into your notebook and fill it in (learn more about this tool at anayaeducacion.es).

Eukaryotic animal cell

Eukaryotic plant cell

Most living beings are made up of eukaryotic cells. There are two different types of eukaryotic cells:

Distinguishing characteristics

Similarities

Distinguishing characteristics

➜ Eukaryotic animal cells, found in animals and

certain unicellular organisms such as protozoa, which you will study later on.

➜ Eukaryotic plant cells, which are found in plants and algae. They have a cell wall and organelles that can only be found in plants. For example, organelles specific to plant cells include chloroplasts, which are specialised in photosynthesis. Large vacuoles are used to store substances.

Eukaryotic animal cell

Nucleus

Eukaryotic plant cell Plasma membrane

Nucleus

Cell wall Plasma membrane

Genetic material (DNA) Mitochondria

Genetic material (DNA)

Chloroplast

Cytoplasm

Cytoplasm Mitochondria Ribosomes

Vacuole

Ribosomes

3 CELLS: THE BUILDING BLOCKS OF LIFE

3.3 Cell size Cells* vary greatly in size. Nevertheless, most cells are microscopic. This means that they cannot be seen with the naked eye. We use a microscope to see them. Cells are measured in units of length known as micrometres (μm).

F ocu s on Eng lish When Robert Hooke looked through a microscope at a thin piece of cork, he saw a series of walled boxes. They reminded him of the small rooms, called cells, that monks lived in. Nowadays, cell is more commonly used as a name for a different type of room; a prison cell.

One micrometre is one thousandth of a millimetre. 1 μm = 0.001 mm 1000 μm = 1 mm Bacteria are the smallest kind of cell. In general, they measure between 1 and 2 micrometres in length. Animal cells vary greatly in size. For example, red blood cells measure 7 micrometres, cells in the liver measure 20 micrometres, sperm cells measure 53 micrometres and egg cells (ovum) measure 150 micrometres. Plant cells vary between 10 and 100 micrometres in length. Some cells in the plant’s epidermis can almost be seen without a microscope!

0.2 μm

15 μm

10 μm

Working with pictures 1 The photos show what cells look like under different microscopes. Look at them and answer the following questions. a) Calculate the true size of the cell by using the scale above each image. b) What kind of cells are they? How do you know? 34

anayaeducacion.es Go to ‘Using a microscope’ in your resource bank.

Unit 1

3.4 Cell shape In addition to having different sizes, cells also have different shapes. Cells can be round, cylindrical, spindle-shaped (fusiform), prismatic, flat or star-shaped. There are other shapes too.

Visual art

C RE AT E A

The shape of a cell is determined by its function. For example, red blood cells are biconcave in shape, like discs with a flattened centre. This allows them to carry as much oxygen as possible.

cells mosaic. Mosaics are a type of work of art made of pieces (called tesserae) of different materials. In the same way as tesserae in a mosaic, cells join together to form tissues and organs. Let’s make a cells mosaic!

Neurons are star-shaped with branches that allow them to communicate with one another. Muscle cells are long, to allow them to contract. The cells covering our organs are usually cube or prism shaped.

Different cell shapes Spermatozoon (sperm cell)

Hepatocyte (liver cell)

Ovum (egg cell)

Adipocyte (fat cell)

Muscle cell Epithelial cells Cone cell

Pigment cell

Red blood cells

Neuron Schwann cell

Working with pictures 2 a) Look at the cells in the picture above. Describe the shape of each one. b) Choose four cells. Find out what their function is. Try to link their shape to the functions they carry out. c) The cells in the picture are not to scale. This means that they are not the same size as in real life. Find out the true size of the cells you picked for question b. Then, put them in order from the smallest to the largest. 35

4 VITAL FUNCTIONS

Living beings perform three vital functions. These are fundamental processes that must be carried out in order to sustain life.

The two types of nutrition

4.1 Nutrition

Autotrophic nutrition Inorganic nutrients are taken in and used to produce organic nutrients. The Sun’s energy

Obtaining nutrients

Inorganic nutrients

Oxygen Carbon dioxide

Nutrition is the vital function through which living beings obtain the matter and energy they need to survive, using the following processes:

Organic nutrients

Carbon dioxide Oxygen

Liquid water and mineral salts

Nutrients can be organic or inorganic. Nutrients are substances that living beings take in. They are used by cells to perform their functions. There are two types of nutrition:

➜ Autotrophic

nutrition means that inorganic substances are taken in and used to synthesise organic nutrients. Examples of inorganic substances include carbon dioxide and the Sun’s energy. This process is known as photosynthesis.

➜ Heterotrophic nutrition means that organic matter from other living beings is consumed in order to produce organic nutrients and energy.

Respiration Heterotrophic nutrition Organic nutrients are obtained through food.

Organic nutrients

Carbon dioxide

Oxygen

Transporting substances Food

Working with pictures Both of the pictures have blue labels naming specific compounds. Which process are these compounds used in? Why are the compounds the same in both pictures?

All living beings take in oxygen (O2) and expel carbon dioxide (CO2) in a process we call respiration. Respiration takes place inside our cells within the mitochondria. In the presence of oxygen (O2) complex molecules are converted into liquid water and carbon dioxide (CO2), which is then released from the cell. This process also generates energy, which cells use to synthesise their components and carry out their functions.

Substances pass in and out of unicellular organisms through the plasma membrane. Multicellular organisms do not come into direct contact with the external environment. Instead, they use specific mechanisms for absorbing, transporting and eliminating substances.

Cellular excretion Excretion is the process of eliminating waste substances, such as CO2 and liquid water. Other substances produced during cellular activity are also eliminated.

Unit 1

4.2 Interaction

Interaction When it is hot, dogs react by sticking their tongues out and panting in order to regulate their body temperature.

Interaction is the vital function through which living beings respond to internal or external changes. It can be broken down into three different stages: Detecting stimuli: receptors Stimuli are the changes that occur in an organism’s internal or external environment and can be perceived by living beings.

Some plants react to light by turning their flowers towards it.

Living beings are able to detect certain stimuli, such as light, heat and movement, with their receptors.

Preparing a response: coordination

Types of reproduction Asexual reproduction

Living beings process the information from the receptors and decide how to respond through a series of processes known as coordination. Coordination can take place within one cell or it can be carried out by complex systems made up of specialised tissues and organs.

Responding: effectors The response prepared during the coordination stage is then carried out by specialist cells called effectors. These effectors produce movement, substances and changes in body shape or function, amongst other things.

4.3 Reproduction Reproduction is the vital function carried out by living beings to create new living beings that are either identical or similar to them. It guarantees species survival. There are two types of reproduction: asexual and sexual. Asexual reproduction Asexual reproduction refers to one single parent (progenitor) producing a copy of itself, by itself. This copy is identical to the progenitor.

Sexual reproduction Sexual reproduction involves one male and one female progenitor. Together, they produce a descendant that is similar to them. Specialised reproductive cells known as gametes are necessary for this process.

Parent cell (progenitor)

Sexual reproduction Male and female gametes come together to create a new living being, which has characteristics that are similar to both progenitors.

Daughter cells (descendants), which are identical to the parent Male gametes

Female gamete

Understand, think, search... 1

1-2-4. Give some examples of stimuli to which living beings can respond.

2 Do you think a unicellular organism can perform the function of interaction? Give reasons for your answer.

3 In your words, explain what asexual reproduction and sexual reproduction are.

5 THE CLASSIFICATION OF LIVING BEINGS

There are many different types of living beings. We use specific criteria to classify them into groups. This helps us to identify them more easily and to study them better. The criteria used to separate them into different groups must be a natural trait.

5.1 Taxonomy Taxonomy is the science of classifying living beings. In the 18 th century, the Swedish botanist Carl Linnaeus began to group living beings together by looking for common characteristics. He organised them into different taxonomic ranks called taxa.

Taxa are groups used to classify living beings. There are seven different taxa, namely: kingdom, phylum, class, order, family, genus and species.

The broadest taxon is called kingdom. Each kingdom groups many different living beings together based on the few characteristics they have in common. The narrowest taxon is called species. Each species is a group of living beings that are so similar they are capable of reproducing with one another to produce fertile descendants. The diagram shows the different taxa.

Carl Linnaeus (1707-1778)

The plant kingdom includes anything from the oak tree to the common fern. The animal kingdom includes living beings from tiny fish to giraffes! Each time we move down a taxon, the living beings included in each group become more similar to one another. This finally brings us to species.

5.2 Binomial nomenclature Linnaeus also introduced binomial nomenclature, where a Latin name was given to all living beings. This name is usually written in italics and consists of two words. The first word, beginning with a capital letter, is the generic name and it identifies the genus. The second word,

which is always written in the lower case, is the specific name and is used only to refer to that specific species. Together, both words form the scientific name. For example, the scientific name for a sparrow is Passer domesticus.

Understand, think, search... Carl Linnaeus is often referred to as the father of taxonomy. Taxonomy is a hierarchical system used to classify living beings into different groups. An organism included in a broader taxa may also appear in the taxa below it. Changes have been introduced ever since Linnaeus first introduced the classification method. Nevertheless, even today, the main principles are still the same.

1 What is a species? 2 Many of the names we commonly use to refer to living beings do not correspond to a specific species. They often refer to groups of species corresponding to higher-level taxa. Which taxa do the following common names refer to: beetle, insect, ant, giraffe?

Find out the scientific name for: the holm oak, the Iberian lynx, and the dog rose.

Unit 1

An example of plant and animal taxonomy

Plants

Angiosperms

Dicotyledons

Asterales

Pseudanthiums

Bellis

Bellis perennis

Kingdom

Animals

Phylum

Arthropods

Class

Insects

Order

Beetles

Family

Scarabaeidae

Genus

Species

Copris

Copris hispanus

Working with pictures Using the diagram above as an example, create a taxonomic classification for the Canis lupus (wolf) and Papaver rhoeas (poppy) species.

anayaeducacion.es Go to ‘How to use a dichotomous key’ in your resource bank.

6 THE FIVE KINGDOMS

6.1 The organisation of living beings Living beings can be unicellular or multicellular.

➜ Unicellular organisms are made up of just one single cell that carries out all the vital functions. They can be prokaryotic or eukaryotic cells.

➜ Multicellular organisms are made up of more than one cell and are always eukaryotic. Most of the time, the cells in multicellular organisms join together to form: • Tissues, which are groups of specialist cells that carry out the same function. • Organs, which are groups of different tissues, designed to carry out a broader function. • Systems, which are made up of different organs and carry out a more complex process.

Levels of organisation in plants

Levels of organisation in animals

form

Cells

form

Cells

which form

which form Tissues

Tissues

which form which form Organs Organs

Living beings

Systems within the living being

Unit 1

6.2 The five kingdoms Organisms are organised into five main groups, based on factors such as:

➜ Cell type. Organisms can be prokaryotic or eukaryotic. ➜ Number of cells. Organisms can be unicellular or multicellular. ➜ Whether or not they have tissues ➜ The type of nutrition performed. Organisms can either be autotrophs or heterotrophs.

These criteria are used to divide living beings into five different kingdoms: Kingdom Monera, Kingdom Protoctista, Kingdom Fungi, Kingdom Plantae and Kingdom Animalia.

Working with pictures Use the picture to answer the following questions: a) Which kingdoms autotrophs?

include

b) Which kingdoms unicellular organisms?

include

c) Which kingdoms include organisms with tissues? d) Which kingdoms include organisms with tissues, organs and systems?

Kingdom Monera Unicellular, prokaryotic organisms which can be either autotrophs or heterotrophs. They sometimes form colonies. Kingdom Protoctista Organisms in this group are made up of eukaryotic cells. They may be made up of one cell (for example, protozoa and microscopic alga) or may be multicellular but not form tissues (for example, larger algae). Protozoa are heterotrophic organisms. Algae are autotrophic organisms. Kingdom Fungi Organisms in this group are made up of eukaryotic cells. They are heterotrophic organisms. There are some unicellular varieties of fungi, for example yeast. Other types are multicellular but do not form tissues. Examples include mould and mushrooms. Kingdom Plantae Organisms in this group consist of eukaryotic cells, with a rigid cell wall and chloroplasts. They are multicellular, made up of tissues and almost always have organs. They are autotrophs. Kingdom Animalia Organisms in this group are made up of eukaryotic cells. They are multicellular, form tissues and almost always have organs and systems. They are heterotrophic organisms.

anayaeducacion.es Go to ‘Are viruses living beings?’ in your resource bank.

ject

research pro

researching Seed germination Project presentation

The term germination refers to the process through which seeds grow into new plants (under the right conditions). During this process, the plant embryo expands, which causes the outer coating of the seed to split. In order for germination to occur, seeds need the right amount of light, correct temperature and an appropriate amount of moisture. Each species has its own specific requirements. Once the seed has germinated, a seedling emerges. As it continues to grow, it is affected by other environmental factors, such as the concentration of salt in the soil (salinity) and the amount of liquid water present.

Project objective

Steps

This experiment consists of three different steps:

➜ Step 1 (in this unit). Doing the necessary background research and project planning in order to plan how you will conduct your experiment.

Methodology

➜ Step 2 (in unit 2). Formulating a hypothesis, then planning and conducting the experiment in order to prove your theory.

➜ Step 3 (in unit 3). Analysing your results and coming to a conclusion. Once you have completed these steps, you should write a scientific article in order to present and explain your findings to the class. 42

UNIT 1

STEP 1

Background research and project planning Planning your work Your teacher will divide the class into groups of three or four students. Once you have been placed in a group, discuss the project and how you intend to carry it out. Divide the work between all members of the group. Before you begin, remember to consult the ‘Steps to be followed in group work’ resource, which is available at anayaeducacion.es. Each group will select two different types of seeds for the experiment. All of the groups should choose different seeds. This will make it possible for the class as a whole to study more seeds of different plant types.

Finding and analysing information Before starting any kind of experiment, you must research the topic that you are going to study. You should try to gather as much information as possible and make sure you consult a variety of different sources. It is also important to check that the sources you use are reliable. Don’t forget to cite your sources when you present your results!

Monocotyledon Dicotyledon

Use your research to answer the questions:

➜ What are seeds? Draw a diagram of a seed and label the different parts.

➜ What differences can you find between the different types of seeds? You could look at lentils, beans, chickpeas and corn, for example. How many cotyledons do the seeds you have chosen have? They should have one or two.

➜ What conditions do you need to ensure that your seeds thrive? ➜ What factors can influence germination? ➜ What is salinity? Where does the salt found in the liquid water used for plants come from? How might salinity affect plants? 43

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AC review and PR

Organising your ideas

Interpreting pictures

3 Name the labelled structures. What type of cell is

In your notebook, fill in the spaces in the concept map and extend its branches. Go to the resource at anayaeducacion.es.

Nutrition

this? 1

? ? Prokaryotic cell

? Formed of cells

Living beings Have the same composition

? ?

Summarising 2 Use these points to write your own unit summary: • What makes life possible on our planet? • What do all living beings have in common?

4 Look at the pictures below and answer the questions: A

• What is the difference between autotrophic and heterotrophic nutrition? And between sexual and asexual reproduction?

• What is the main difference between prokaryotic

cells and eukaryotic cells?

• What is the main difference between eukaryotic

animal cells and eukaryotic plant cells?

• What are the main taxa for classifying living beings?

• What is a species? Can you think of two examples? Give the scientific name and the common name.

• What are the five kingdoms of living beings? What are their main characteristics?

• What are: a) The kingdoms with prokaryotic cells and the kingdoms with eukaryotic cells? b) The kingdoms with beings that have tissues and the kingdoms with beings that don’t have tissues? c) The kingdoms with beings that only use autotrophic nutrition, the kingdoms with beings that only use heterotrophic nutrition, and the kingdoms with beings that use both types of nutrition?

a) What kingdom does each living being belong to? b) Which living being are unicellular and which are multicellular? c) Which form tissues and which don’t? Which have organs? Which have systems? d) What type of nutrition and reproduction does each living being use? anayaeducacion.es Go to ‘Science workshop: observing plant cells under a microscope’ in your resource bank.

UNIT 1

Applying your knowledge

Moving forward

5 Are the following statements about cell components

10 Read this text and answer the questions:

true or false? a) Nucleic acids are the main source of cell energy. b) Proteins are important because of their structure and their regulatory functions. c) Lipids are carbohydrates that regulate cell activity. d) The genetic material of cells is composed mainly of nucleic acids.

6 If 5 kg of animal mass contains approximately 10 000 000 million cells: a) How many millions of millions of cells are there in a human being with a mass of 55 kg?

Some animals, like starfish and lizards, can regenerate amputated parts of their bodies. Human beings can’t regenerate an arm or a leg, but our bodies are constantly regenerating cells like those in our blood, our skin and our liver. But not all the cells in our bodies can regenerate; differentiated cells, for example, have lost the ability to make copies of themselves. Cells that can regenerate are called stem cells. Stem cells can multiply and transform into any type of cell in order to replace others that are damaged or old. They act as reserves for regenerating different parts of the body.

b) How many millions of millions of cells are there in an elephant with a mass of 6 800 kg? c) What is the approximate mass of one animal cell?

7 A protozoan measuring 110 micrometres was observed in a sample of pond water. a) If we put 1 320 similar protozoa in a line, how long would the line be? b) How many protozoa would you need to make a line measuring 250 metres?

8 Are the these statements true or false? a) Fungi use solar energy to make their organic nutrients. b) Plants use solar energy to make their organic nutrients. c) Plants don’t use energy from food because they use energy from sunlight. d) All living beings extract the energy they need from organic nutrients.

9 Do the following words refer to a type of cell, tissue, organ or system? a) Lymphocyte b) Skin c) Digestion d) Neuron e) Heart f) Circulatory

a) Can all the body’s cells regenerate? Give some examples to support your answer. b) Do you think it is possible to regenerate any tissue from stem cells? c) Do some research and describe how stem cells are used.

Sustainable Development Goals 11 According to Sustainable Development Goal 13, greenhouse gas emissions have caused an increase of 0.85 °C in the planet’s average temperature. This is having serious consequences, such as ocean warming, melting ice and rising sea levels. If things continue as they are, the global temperature could increase by 1.5 °C by the middle of the century. Look at the information about Target 13.3 (at anayaeducacion.es) and answer the following questions. a) If the planet’s average temperature increases as predicted, what will it be by the middle of the century? And by the end of next century? b) Do some research and describe how greenhouse gases affect the climate. c)

anayaeducacion.es Go to ‘Key concepts’ and ‘Learn by playing’ in your resource bank.

In groups, think of some measures you could take to educate people around you about the dangers of climate change.

Glossary

A Asexual reproduction A type of reproduction where a single living being can produce one or more offspring that are identical to it. Atmosphere The layer of gases surrounding the Earth. Atoms Tiny units that make up all the matter in the universe.

Cytoplasm The jelly-like fluid that fills the inside of a cell.

E Eukaryotic cell A type of cell in which the genetic material is contained in a nucleus surrounded by a membrane, and which consists of many different organelles.

Autotrophic nutrition A type of nutrition where living beings can produce their own nutrients from substances like water, minerals and carbon dioxide using energy from the Sun.

B Binomial nomenclature A system for assigning unique names to organisms. Linnaeus was the person who created it. The names are in Latin and consist of two words written in italics: the first word indicates the genus and the second word indicates the species. Biomolecules Substances that are unique to living beings. Biosphere The part of the Earth where all life exists.

C Carbohydrates Biomolecules that provide energy to a cell. Cell The most basic unit of a living being. A cell can perform the three vital functions.

G Genetic material A fibrous substance called DNA that controls cell function. Geosphere The solid layer of the Earth formed of rocks and minerals.

H Heterotrophic nutrition A type of nutrition where living beings get the nutrients they need from other living beings or their remains. Hydrosphere The part of the Earth formed of oceans, seas, rivers, lakes and other bodies and currents of water.

I Inorganic substances Substances that are present in living beings and non-living matter, for example water and mineral salts.

Cell organelles Small structures in a cell that are specialised to perform different functions.

Interaction A vital function that allows living beings to receive information from their external environments or from within their bodies, and respond to that information appropriately to ensure their survival.

Unit 1

L Lipids Biomolecules that perform various functions like energy storage and heat insulation. Some lipids form part of the plasma membrane of cells.

Prokaryotic cell A type of cell that lacks a nucleus, and in which the genetic material exists freely in the cytoplasm.

M Membrane A thin and flexible casing that surrounds a cell and regulates the exchange of substances with the outside. Micrometre or micron A unit of length equal to one millionth of a metre. Multicellular organisms Living beings formed of more than one cell.

N Nucleic acids Large biomolecules containing the information that organisms need to function. DNA is a nucleic acid.

Proteins Complex biomolecules that perform a variety of functions in living beings, like forming cell structures, defending the organism from microorganisms, and muscle contractions.

S Sexual reproduction A type of reproduction where two living beings, one male and one female, provide specialised cells called gametes, which combine to create one or more offspring that are similar to the parent organisms. Species A taxonomic group for classifying living beings, comprising individuals that are similar enough to be able to reproduce with one another and produce fertile offspring.

Nutrients Organic and inorganic substances that living beings eat and that are useful for their cells.

O Organs Parts of the body that are made up of different tissues and perform a specific function.

T Taxa The groups into which we classify living beings, that is, kingdom, phylum, class, order, family, genus and species. Tissues Groups of coordinated cells that are specialised to perform a particular function.

P Phylum A taxonomic group for classifying living beings, made up of life forms that share general characteristics. A phylum falls within a kingdom and is divided into classes. Examples of phyla are arthropods and molluscs.

U Unicellular organisms Living beings formed of a single cell. 47

Building Blocks is an educational project of Anaya Educación for Secondary Education with the participation of: Danny Latimer, Hannah Peat, Karen Piper, Denise Suárez, Begoña Fuente Larrazabal, Sara Gascón Martin, S. Clemente, A. Domínguez, A. B. Ruiz. The following people have also contributed to this book:

Editorial team:

Hannah Peat and Departamento de Ciencias Naturales (Almudena Alcón, Esther Fernández, Mª Isabel García, Marco Sánchez, Mercedes Sacristán and Jorge Torres).

inclusion and anti-discrimination Advisor: Víctor Díez Mazo. Design, technical drawings and maps: Patricia G. Serrano, Juan Carlos Quignón, Miguel A. Castillejo, Miguel A. Díaz-Rullo and Miriam Arribas.

Illustrations: Sara Mateos, Celia López Bacete, Santi Martín, Alicia Posada, Mª Carmen Fuente, David Menéndez and Carlos Moreno.

Layout:

Mª Nieves Merino and Oscar Latorre.

Corrections: Departamento de correcciones de Anaya Educación. Translation: Montero Language Services. Proofreading: Rachel Bland (Bakun S. L.) Graphic edition: Olga Sayans. Photographs:

Age Fotostock (AndreyPopov, ARCO / Muehlmann, K., Auscape / UIG, BILDAGENTUR-ONLINE/ MCPHOTO-SCHULZ, BRITISH ANTARCTIC SURVEY, DENNIS KUNKEL MICROSCOPY-SPL, E R Degginger, GERD GUENTHER, J M Barres, JANNICKE WIIK-NIELSEN, Jens Meyer, Jerónimo Alba, Lucas Vallecillos, Michael Abbey, Nasa via ZUMA Wire, ROGELIO MORENO, Science Photo Library, Spike Walker, STEVE GSCHMEISSNER, Wim van Egmond), Agencia EFE (EFE/lafototeca.com) Alamy/Cordon Press (Anne-Marie Palmer, blickwinkel, cbimages, Greenshoots Communications, jeremy sutton-hibbert, Nino Marcutti, Valentyn Volkov, YAY Media AS), Archivo Anaya (Alcón, A. and Santos, V.E.; Candel, C.; Canto, M.; Cosano, P.; Cruz, M.; CSIC/IFI/Barcenilla, J.; Hernández Moya, B.; Lezama, D.; Martín, J. A.; Martínez, C.; Moreno, C.; Muñoz, M.; Ortega, A.; Padura, S.; Peñuela Py, E.; Pozo, M.; Quintas, D.; Ramón Ortega, P.-Fototeca España; Rico, J.J.; Rivera Jove, V.; Ruiz, J.B.; Sanz, C.; Steel, M.; Sánchez, J.; Valls, R.; Velasco, P-Fototeca España; Zuazo, A.H.), Dreamstime (Ekinaa, Fokinol, Sarah 2), GettyImages (Hero Images, Jason Edwards), GSFC Ozone Processing Team, iStock/Gettyimages, Mediateca DGT, NASA/ESA/The Hubble Heritage Team (STScI/AURA), NASA/JPL-Caltech/R. Hurt (SSC/Caltech), NASA/ JPL-Caltech/University of Arizona, NASA/NASA Ozone Watch/Katy Mersmann, Nature Picture Library/CordonPress (Andy Rouse, Anup Shah, Chris & Monique Fallows, David Shale, Linda Pitkin, Richard Robinson, Tony Wu, Yukihiro Fukuda), 123rf and collaborators.

Special thanks to Ana Codeseda for writing the scientists’ biographies. Other thanks: to Almudena Monge for permission to use the field notebook illustation.

Academic and Professional Orientation: created in conjunction with Fundación Bertelsmann. Coordinator: Juan José Juárez Calvo. Expert collaborators: Sara Lozano Santiago, Belén Pérez Castro and Pilar Vázquez Hernández.

Commitment to Sustainable Development Goals Our publications contain carefully selected content, illustrations and language to comply with non-discrimination on the grounds of gender, culture or opinion. Grupo Anaya considers social and environmental responsibility to be one of its fundamental values. For this reason, we are committed to: · continually improving our contents and materials related to the environment. · reducing our carbon emissions. · using natural resources responsibly. · making sure that our activity has no negative consequences for endangered forests. These commitments, among others, mean that 100% of the paper used in our books has the PEFC label. Important information: The activities proposed in this book should be completed in a separate notebook or on sheets of paper, not in the book itself. The links to webpages which appear in this book have been checked before printing. The publisher cannot be liable for any changes or modifications which occur after the date of publication. © GRUPO ANAYA, S.A., 2021 - C/ Juan Ignacio Luca de Tena, 15 - 28027 Madrid. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of the publishers.

e d

a c r ce

DEMO

biología y geolo gía

1 ESO

Building

Blocks

Building Blocks es un proyecto educativo de Anaya para Educación Secundaria con la participación de:

CONTENIDOS: Berta Gallego (adaptación de los contenidos del libro de Biología y Geología 1.° ESO). Equipo de edición: Departamento de Ciencias Naturales (Almudena Alcón, Esther Fernández, Mª Isabel García, Marco Sánchez, Mercedes Sacristán, Jorge Torres y Hannah Peat).

Asesoramiento para la inclusión y la no discriminación: Víctor Díez Mazo. Diseño, gráficos y cartografía: Patricia G. Serrano, Juan Carlos Quignon, Miguel Á. Castillejo, Miguel Á. Díaz-Rullo y Miriam Arribas.

Ilustración:

Sara Mateos, Celia López Bacete, Santi Martín, Alicia Posada, M.ª Carmen Fuente, David Menéndez y Carlos Moreno.

Maquetación: Óscar Latorre y Elvira López. Corrección: Sergio Borbolla. Edición gráfica: Olga Sayans. Fotografía: Age Fotostock (AndreyPopov, ARCO / Muehlmann, K., Auscape / UIG, BILDAGENTUR-ONLINE/MCPHOTO-SCHULZ, BRITISH ANTARCTIC SURVEY, DENNIS KUNKEL MICROSCOPY-SPL, E R Degginger, GERD GUENTHER, J M Barres, JANNICKE WIIK-NIELSEN, Jens Meyer, Jerónimo Alba, Lucas Vallecillos, Michael Abbey, Nasa via ZUMA Wire, ROGELIO MORENO, Science Photo Library, Spike Walker, STEVE GSCHMEISSNER, Wim van Egmond), Agencia EFE (EFE/lafototeca.com) Alamy/Cordon Press (Anne-Marie Palmer, blickwinkel, cbimages, Greenshoots Communications, jeremy sutton-hibbert, Nino Marcutti, Valentyn Volkov, YAY Media AS), Archivo Anaya (Alcón, A. y Santos, V.E.; Candel, C.; Canto, M.; Cosano, P.; Cruz, M.; CSIC/IFI/Barcenilla, J.; Hernández Moya, B.; Lezama, D.; Martín, J. A.; Martínez, C.; Moreno, C.; Muñoz, M.; Ortega, A.; Padura, S.; Peñuela Py, E.; Pozo, M.; Quintas, D.; Ramón Ortega, P.-Fototeca España; Rico, J.J.; Rivera Jove, V.; Ruiz, J.B.; Sanz, C.; Steel, M.; Sánchez, J.; Valls, R.; Velasco, P-Fototeca España; Zuazo, A.H.), Dreamstime (Ekinaa, Fokinol, Sarah 2), GettyImages (Hero Images, Jason Edwards), GSFC Ozone Processing Team, iStock/Gettyimages, Mediateca DGT, NASA/ESA/The Hubble Heritage Team (STScI/AURA), NASA/JPL-Caltech/R. Hurt (SSC/Caltech), NASA/JPL-Caltech/University of Arizona, NASA/NASA Ozone Watch/Katy Mersmann, Nature Picture Library/CordonPress (Andy Rouse, Anup Shah, Chris & Monique Fallows, David Shale, Linda Pitkin, Richard Robinson, Tony Wu, Yukihiro Fukuda), 123rf y colaboradores.

compromiso Nuestras publicaciones mantienen el rigor en el uso y en la selección de los contenidos, en las imágenes y en el lenguaje, para cumplir con la no discriminación por razón de género, cultura u opinión. Grupo Anaya considera la responsabilidad social y medioambiental uno de sus valores fundamentales. Por ello, se compromete a: · mejorar nuestros resultados en materia de medio ambiente, · reducir nuestras emisiones de carbono, · hacer uso de los recursos naturales de manera responsable y · eliminar cualquier impacto negativo de nuestra actividad en los bosques en peligro. Dichos compromisos, entre otros, hacen que el 100 % del papel utilizado en nuestros libros tenga el sello PEFC. Importante: Las actividades propuestas en este libro deben ser realizadas en cuadernos u hojas sueltas; nunca en el propio libro. Los enlaces a las páginas web que aparecen en este libro han sido revisados en la fecha de su impresión. La editorial no se hace responsable de las modificaciones o las anulaciones que se produzcan en ellos con posterioridad a dicha fecha.

© GRUPO ANAYA, S.A., 2021 - C/ Juan Ignacio Luca de Tena, 15 - 28027 Madrid. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of the publishers.

ÍNDICE El método científico..................................................... 4 1 El método científico paso a paso • 2 La investigación en el laboratorio • 3 La investigación en el medio natural • 4 Búsqueda de información

1. Los seres vivos.................................................................... 8

6. Los ecosistemas...............................................................38 1 Cómo es un ecosistema • 2 Las relaciones bióticas • 3 Las relaciones tróficas • 4 Los ecosistemas terrestres: los biomas • 5 Los ecosistemas acuáticos y el suelo como ecosistema • 6 La conservación de los ecosistemas

1 La Tierra y sus condiciones para la vida • 2 La composición de los seres vivos • 3 La unidad de la vida: la célula • 4 Las funciones vitales • 5 La clasificación de los seres vivos • 6 Los cinco reinos de la vida

7. El universo........................................................................... 44

2. Moneras protoctistas y hongos................... 14

8. La atmósfera y la hidrosfera......................... 50

1 El reino de los moneras • 2 El reino de los protoctistas. Los protozoos • 3 El reino de los protoctistas. Las algas • 4 El reino de los hongos

3. Las plantas............................................................................18 1 El reino de las plantas • 2 La clasificación de las plantas 3 Funciones vitales en las plantas: la nutrición • 5 Funciones vitales en las plantas: la relación • 6 Funciones vitales en las plantas: la reproducción

4. Los animales. Funciones vitales....................24 1 El reino de los animales • 2 La nutrición en los animales: la obtención de nutrientes • 3 La nutrición en los animales: la respiración • 4 La nutrición en los animales: la circulación y la excreción • 5 La relación en los animales: los órganos sensoriales • 6 La relación en los animales: la coordinación y los efectores • 7 La reproducción en los animales

5. Los animales. CLASIFICACIÓN................................32 1 Los poríferos, los cnidarios y los gusanos • 2 Los moluscos y los equinodermos • 3 Los artrópodos • 4 Los peces y los anfibios • 5 Los reptiles y las aves • 6 Los mamíferos

1 El universo • 2 Las galaxias y las estrellas • 3 El sistema solar • 4 La Tierra y la Luna • 5 Los movimientos de la Tierra • 6 Los eclipses y las mareas

1 La atmósfera terrestre • 2 La importancia de la atmósfera para la vida • 3 La contaminación del aire y sus consecuencias • 4 El agua: propiedades y distribución • 5 El ciclo del agua. Los usos del agua • 6 La contaminación del agua y su gestión sostenible

9. La geosfera Las rocas y los minerales.................................. 56 1 La geosfera • 2 Los minerales • 3 Las rocas • 4 Los recursos de la geosfera y el ser humano

GLOSARIO................................................................................... 60

D iDA

LOS SERES VIVOS

1 LA TIERRA Y SUS CONDICIONES PARA LA VIDA

La presencia de atmósfera

¿Cómo es la Tierra? La Tierra es un planeta sólido, formado principalmente por rocas. Está rodeado de una capa de gases y presenta agua líquida en su superficie.

La existencia de estaciones y de días y noches

Estos componentes forman lo que se han denominado las cuatro capas o «esferas», que interaccionan entre sí: • La biosfera es la capa formada por todos los seres vivos que habitan el planeta. • La atmósfera es la capa de gases que envuelve la Tierra.

Las condiciones que permiten la vida en la Tierra

• La hidrosfera está formada por toda el agua del planeta. • La geosfera es la parte sólida y está formada por las rocas y los minerales.

Las condiciones necesarias para la vida Nuestro planeta es el único del sistema solar que alberga seres vivos debido a que se dan en él unas condiciones muy especiales:

La presencia de agua líquida

• La distancia de la Tierra al Sol es la ideal para el desarrollo de la vida. • La atmósfera ejerce un efecto protector frente a algunas radiaciones solares y, contiene dos gases, el oxígeno y el dióxido de carbono, necesarios para la respiración y la fotosíntesis.

La adecuada distancia de la Tierra al Sol.

• La temperatura suave, de unos 15 °C, permite la presencia de agua líquida. 1

• La existencia de estaciones y la rápida sucesión del día y la

3 2

Comprende, piensa, investiga...

1 ¿Cuáles de las siguientes frases son verdaderas?

d) La biosfera está formada por el conjunto de seres vivos que habitan en el planeta.

Corrige las falsas: a) La capa de gases que envuelve la Tierra es la atmósfera.

2 Observa la imagen superior e indica a qué capa

b) Las bajas temperaturas de la Tierra permiten la vida de los seres vivos.

c) Una mayor distancia al Sol impediría la vida en nuestro planeta.

de la Tierra corresponde cada número. Lee el texto «Agua líquida» disponible en el banco de recursos de anayaeducacion.es y explica por qué es importante que haya agua en estado líquido en el planeta.

2 LA COMPOSICIÓN DE LOS SERES VIVOS • Los seres vivos están compuestos por el mismo tipo de sustancias: sustancias orgánicas e inorgánicas. • Los seres vivos se organizan a partir de unidades similares: las células.

Sales minerales

• Los seres vivos realizan las tres funciones vitales: la nutrición, la relación y la reproducción.

Agua

La composición química de la vida

Sustancias inorgánicas

Los seres vivos están formados por dos tipos de sustancias:

Las sustancias inorgánicas Estas sustancias se encuentran presentes tanto en los seres vivos como en la materia no viva. Son el agua y las sales minerales. • El agua es un componente esencial de los seres vivos y desempeña un papel fundamental en la mayoría de las transformaciones que tienen lugar dentro de las células.

Los seres vivos están formados por

• Las sales minerales intervienen en la regulación de muchos procesos vitales.

Las sustancias orgánicas Estas sustancias, también llamadas biomoléculas, son exclusivas de los seres vivos. Son los glúcidos, los lípidos, las proteínas y los ácidos nucleicos.

Comprende, piensa, investiga... 1 Di a qué sustancia hace referencia cada una de las frases siguientes: a) Sirven como reserva energética y forman parte de estructuras celulares.

Sustancias orgánicas Proteínas Las proteínas intervienen en multitud de procesos, pero destacan las funciones estructurales.

Ácidos nucleicos Contienen la información necesaria para el funcionamiento de la célula.

b) Junto con el agua, es una de las sustancias inorgánicas que componen los seres vivos. c) Es la sustancia más abundante en los seres vivos. d) La más conocida es el ADN.

Lee el texto «Las funciones de las proteínas» disponible en el banco de recursos de anayaeducacion.es y completa en tu cuaderno los huecos vacíos. a) La … transporta el oxígeno en la sangre. b) La ovoalbúmina sirve como sustancia de ...

Lípidos Almacenan energía, proporcionan aislamiento térmico y forman parte de algunos componentes celulares.

Glúcidos Proporcionan energía a la célula.

c) La actina y la … son responsables de la ... muscular d) La insulina es una ... que regula la cantidad de ... en la sangre.

3 LA UNIDAD DE LA VIDA: LA CÉLULA

¿Cómo son las células?

Célula procariota

Por lo general, las células son microscópicas, es decir, no son observables a simple vista, sino que debe utilizarse un microscopio. La unidad que se utiliza para medir las células es el micrómetro o micra (μm). Todas las células tienen las siguientes estructuras:

Membrana plasmática

Pared celular

Material genético (ADN) Citoplasma

• La membrana plasmática, que es una fina capa protectora y reguladora de la entrada y la salida de sustancias con el medio externo.

Ribosomas

• El citoplasma, que es el medio acuoso del interior celular. Flagelo

• El material genético, que es un conjunto de fibras de ADN que contiene la información para controlar el funcionamiento de la célula.

Célula eucariota animal

• Los orgánulos celulares, que son pequeñas estructuras especializadas en determinadas funciones. Varían según el tipo de Núcleo

Citoplasma Membrana plasmática

Tipos de células

Mitocondria

Existen dos tipos de células: las procariotas y las eucariotas.

Las células procariotas Las células procariotas son aquellas que no tienen núcleo, por lo que su ADN está disperso en el citoplasma.

Material genético (ADN)

Ribosomas

Célula eucariota vegetal

Presentan pared celular y un solo tipo de orgánulo, los ribosomas, cuya función es sintetizar proteínas. Pueden tener flagelos, filamentos que utilizan para moverse.

Núcleo Citoplasma

Las células eucariotas Las células eucariotas tienen el ADN rodeado de una membrana, formando el núcleo. Tienen membrana plasmática y citoplasma, en el que, además de ribosomas, hay gran variedad de orgánulos. Las células eucariotas forman la mayoría de los seres vivos y se clasifican en eucariotas de tipo animal y de tipo vegetal.

Membrana plasmática

Pared celular Mitocondria

Material genético (ADN)

Cloroplasto Vacuola

Ribosomas

Comprende, piensa, investiga... 1 Di a qué estructura celular se hace referencia en cada caso: a) Son estructuras especializadas y su presencia varía según el tipo de célula. b) Es el medio en el que se encuentran todos los componentes celulares.

2 Observa las imágenes de los tipos de células. Copia y completa la tabla en tu cuaderno.

Estructura Núcleo Mitocondria Cloroplasto Ribosomas Membrana plasmática Pared celular Vacuola

Célula Célula eucariota Célula eucariota procariota animal vegetal No Sí Sí ? ? ? ? ? ?

? ? ? ? ? ?

Unidad 1

4 LAS FUNCIONES VITALES

Nutrición La nutrición es la función vital que permite a los seres vivos obtener la materia y la energía que La nutrición se lleva a cabo a través de: la obtención de nutrientes, la respiración, la distribución de sustancias y la excreción.

Comprende, piensa, investiga... 1 Observa la ilustración del proceso de nutrición en las plantas y completa el texto en tu cuaderno: 1 En la primera etapa del proceso, la planta obtiene los nutrientes. Primero, absorbe ... y ... ... a través de las raíces, y ... de ... a través de las hojas. Mediante la fotosíntesis, la planta transforma estas sustancias en nutrientes …

Hay dos tipos de nutrición: • Nutrición autótrofa. Consiste en obtener nutrientes orgánicos a partir de nutrientes inorgánicos, como el dióxido de carbono, y de la energía solar. Este proceso se denomina fotosíntesis. • Nutrición heterótrofa. Consiste en obtener los nutrientes orgánicos y la energía a partir de la materia orgánica de otros seres vivos.

Relación

2 Mediante el proceso de … la planta obtiene energía a partir del oxígeno que toma del aire y de los nutrientes orgánicos formados. 3 Los nutrientes orgánicos se … por toda la planta. 4 Las sustancias de desecho procedentes de las actividades celulares se eliminan mediante el proceso de …

La relación es la función vital a través de la cual los seres vivos son capaces de responder a los cambios que se producen en el medio que les

Energía

El proceso se realiza en las siguientes etapas:

• Percepción de estímulos. Los seres vivos tienen receptores para captar los cambios que se producen en el interior o el exterior de su organismo. • Elaboración de la respuesta: la coordinación. Los seres vivos procesan la información recogida por los receptores y elaboran una respuesta. • Ejecución de la respuesta: los efectores. Las respuestas elaboradas por los órganos de coordinación son ejecutadas por los efectores. Estos generan movimientos, segregan sustancias…

Reproducción

Respiración

Fotosíntesis Nutrientes orgánicos

Absorción de CO2 1

Obtención de nutrientes

Distribución de sustancias 4

Agua 1a

CO2

Excreción

CO2

Absorción de agua y sales minerales

La reproducción es la función vital que realizan los seres vivos cuando generan nuevos organismos semejantes a ellos, asegurando así la super• Reproducción asexual. Consiste en producir, a partir de un único individuo progenitor, un descendiente idéntico a él. • Reproducción sexual. Aquella en la que dos individuos progenitores de distinto sexo (masculino y femenino) generan descendientes semejantes a ellos.

Lee el texto «Gametos» disponible en el banco de recursos de anayaeducacion.es y describe en tu cuaderno la diferencia entre el espermatozoide y el óvulo.

5 LA CLASIFICACIÓN DE LOS SERES VIVOS

Taxonomía La taxonomía es la ciencia que clasifica los seres vivos. De acuerdo con ella, los seres vivos se pueden agrupar según sus características comunes, en niveles o grupos de clasificación denominados taxones.

Los taxones son los grupos en que se clasifican los seres vivos. Son el reino, el filo, la clase, el orden, la familia, el género y la

El taxón más amplio es el reino, que agrupa muchos individuos con pocas características en común. El taxón menos amplio es la especie, que agrupa a individuos tan semejantes que pueden reproducirse entre sí dando descendencia fértil.

Nomenclatura binomial Las especies de seres vivos se nombran de acuerdo con la nomenclatura binomial, un nombre en latín, formado por dos palabras escritas en letra cursiva: la primera palabra comienza con letra mayúscula y nos indica el género al que pertenece el individuo. La segunda se escribe siempre en minúscula y es exclusiva de la especie. Estas dos palabras forman el nombre científico.

Reino

Comprende, piensa, investiga... 1 Observa la ilustración de la derecha. En ella se indican los taxones y el nombre del mismo para la clasificación del escarabajo. Según esto, relaciona y coloca en orden en tu cuaderno los taxones con su nombre correspondiente para la clasificación del oso polar:

Insectos

Orden

Coleópteros

Familia

Escarabeidos

Lee el texto «Linneo, el padre de la taxonomía» disponible en el banco de recursos de anayaeducacion.es y escribe las opciones correctas en tu cuaderno:

Género

Copris

a) Linneo fue un microbiólogo del siglo xviii.

Especie

Copris hispanus

Filo

Orden Úrsidos

Cordados

Familia

Reino

Ursus maritimus

Genéro

Carnívoros

Clase

Mamíferos

Especie

b) Linneo utilizó el nombre de los seres vivos en latín. c) El nombre científico es el mismo en todos los idiomas.

Artrópodos

Clase

Animales

Filo

Animales

Ursus

Unidad 1

6 LOS CINCO REINOS DE LA VIDA

Los cinco reinos Los seres vivos se pueden clasificar en cinco reinos: el de los moneras, el de los protoctistas, el de los hongos, el de las plan-

• Son procariotas. • Son unicelulares y, a veces, forman colonias. • Ejemplo: bacterias.

Reino de los moneras

• Son eucariotas. • Los hay unicelulares y pluricelulares sin tejidos verdaderos. • Pueden tener nutrición autótrofa o heterótrofa. • Ejemplos: algas y protozoos.

Reino de los protoctistas Protozoo

Alga

Reino de los hongos

Levaduras

Mohos

• Son eucariotas. • Los hay unicelulares y pluricelulares sin verdaderos tejidos. • Su nutrición es heterótrofa y son descomponedores. • Ejemplos: levaduras y hongos que forman setas.

Setas

Reino de las plantas

Reino de los animales

• Son eucariotas. • Son pluricelulares con tejidos. La mayoría tienen órganos. • Su nutrición es autótrofa.

• Son eucariotas. • Son pluricelulares con tejidos. Casi siempre con órganos. • Su nutrición es heterótrofa.

Comprende, piensa, investiga... 1 Lee el texto «Los criterios de clasificación» disponible en el banco de recursos de anayaeducacion.es y completa en tu cuaderno los huecos vacíos. a) Según el tipo de célula, los seres vivos pueden ser ... o ... b) De acuerdo con el número de células, pueden ser ... o ... ...

c) Otro criterio es si tienen o no ... d) Según el tipo de nutrición, pueden ser ... o ...

2 Elabora una tabla en tu cuaderno para indicar las características de cada reino de acuerdo con su: tipo de célula, número de células, presencia o ausencia de tejidos y tipo de nutrición.