Education is a long road that lasts a lifetime. Follow the WORLD MAKERS learning path to create a more equal, fair and sustainable world. Learning path LEARNING SITUATION. THE CHALLENGE 1 THE SUSTAINABLE DEVELOPMENT GOALS 2 Remember what you already know about the topic, your previous knowledge acquired in previous years, in other units or in your own daily life. Think about an everyday life situation and put yourself in the place of the characters who present it. Contribute to the achievement of one or several targets of the Sustainable Development Goals (SDGs). Use your book to find the answers. Look for reliable information on the internet, in other books, from the people around you… Analyse it and then draw your conclusions to answer the questions. Critical thinking. Discuss whether the information is true or not. In the TRUE OR FALSE? section, you will find suggestions for learning how to create truthful content and for deconstructing fake news and myths. Research, think and then answer the questions that will help you complete the challenge and acquire core skills. 4. The Fungi kingdom Compare fresh yeast and chemical yeast You are going to test carbon dioxide production in fresh yeast (a paste of live fungus cells) and in chemical yeast. Material Chemical yeast and fresh yeast Four test tubes Sugar and water The importance of fungi Fungi cause diseases in humans, animals and plants. However, they are also ver y important in other areas: The environment. They help to recycle organic matter in the soil . They play a fundamental role in the formation of mature soils. Food . Many mushrooms are edible and form part of our diet. However, others are toxic and can be deadly. Yeasts are used to produce bread and alcoholic drinks, such as wine and beer. This process is called fermentation. Yeast uses carbohydrates and produces carbon dioxide and other substances. Health. In 1928, Alexander Fleming identified a mould , Penicillium notatum. It released a substance that killed the bacteria growing around it. This substance was penicillin , an antibiotic that revolutionised medicine. Moulds are also used to produce some cheeses, such as blue cheese. Steps 1. Fill the four test tubes halfway with warm water. 2. Label the tubes 1 to 4 so that you can identify them. 3. Then add the items in the table below to each tube. 4. Finally, stir them and write down what happens in your notebook. Conclusions 20 Were bubbles produced in all the samples? Did the samples take the same amount of time to produce the bubbles? Explain the results in a table. Tube 1 Tube 2 Tube 3 Tube 4 Warm water Warm water Warm water Warm water Fresh yeast Fresh yeast Chemical yeast Chemical yeast Tablespoon of sugar … Tablespoon of sugar … 104 ES0000000100241 959327_Unidad05_105215.indd 104 28/12/21 9:10 4 Heterotrophic organisms Heterotrophs cannot produce their own organic substances, so they get it by feeding on other living things. Heterotrophic organisms include animals, fungi , some bacteria and other microorganisms, such as protozoa . Parasites feed on other living things, and they cause harm. For example, ticks bite dogs so that they can feed on their blood , and this causes wounds. Herbivores feed on plants. Omnivores feed on plants and animals. Carnivores feed on other animals. Detritivores are animals that feed on the remains of other living things. For example, millipedes feed on fallen leaves. There are also some special types of heterotrophic organisms, such as: Can we sleep with plants in the bedroom? You might have heard that it is not a good idea to sleep with plants in the room because they use the oxygen. Plants produce their own food through photosynthesis. During this process, they release oxygen into the atmosphere. Because this requires light, it cannot take place at night. However, the process of respiration continues, during which plants take in oxygen from the air and release carbon dioxide. But the oxygen that a plant consumes is a tiny amount. It is much less than an animal needs, so a plant will never consume all the oxygen in a room. In 1989, NASA published an article about the benefits of indoor plants. Look for information about it. Then write down the benefits of some of the plants mentioned in the article. Caterpillar Shrew Badger Decomposers include fungi and some bacteria that break down the organic substances left by detritivores. OR FALSE T R U E ? 81 ES0000000100241 959327_Unidad04_104476.indd 81 28/12/21 9:09 Do experiments and carry out simple practical activities. Complete the steps by applying what you have learnt. Acquire essential knowledge from content explained in a very clear way and with strong visual support: photos, drawings, diagrams, etc. Make a list of ten living things. Then list another ten objects that have never been alive. What do all living things have in common? WORK WITH THE IMAGE - What life process is shown in the photo on the right? - What type of reproduction involves two living things of different sexes? - What other life processes are there? WORK WITH THE IMAGE . Look at the photo on the previous page. - Why are bees important for people? - Bees are also important for plants. Explain why. WORK WITH THE IMAGE - How many living things can you see in the photo on the left? - How are they different from each other? How many groups of living things do you know? Give an example from each group. L E T ' S G E T S TA R T E D Sarah likes to know what is happening in the world . She is worried because she has heard about living things in danger of extinction . She thinks that all living things are important. People need to be made aware of the problem so they can protect them. For this reason , Sarah suggests that her class creates some posters to explain the importance of living things in dif ferent habitats. The murals can be displayed at school and at a cultural centre nearby. The biosphere 4 Design posters that explain why living things are important. CHALLE NGE IN THIS UNIT. . . 1 Living things 2 Cells 3 Life processes 4 The classification of living things 5 The five kingdoms Take act ion Biodiversity is essential and for many reasons we have a duty to protect it. This challenge looks at the ways living things are useful to people, and their importance to other living things. Target 15.5: "Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity and protect and prevent the extinction of threatened species." L E A R N I N G S C E N A R I O 73 72 ES0000000100241 959327_Unidad04_104476.indd 73 28/12/21 8:58 Eukar yotic cells Prokar yotic cells Cells have many dif ferent shapes and sizes. They are classified into two groups: prokar yotic cells and eukar yotic cells. Both groups have some structures in common : 6 Explain what cells are. Why are they such an important part of living things? 7 How are cells classified? Give an example of a living thing for each cell type. 8 What structures do prokaryotic and eukaryotic cells have in common? How are they different? 9 What structures are only found in plant cells? 10 WORK WITH THE IMAGE. Look at the photo on the right. Find out what type of cells these living things are made of. Then describe the cells. 4 2. Cells The smallest and simplest cells. They are found in bacteria, which are unicellular organisms. These cells are much bigger and more complex than prokar yotic cells. Their cytoplasm has lots of organelles. Their genetic material is surrounded by a membrane that forms a nucleus. They are found in all multicellular organisms and in some unicellular organisms. Animals and plants have many dif ferent types of cells. The cells that carr y out the same function join together to form tissues. For example, muscular tissue and ner ve tissue in animals. Mitochondria. Organelles that are involved in cellular respiration . Cell membrane Cytoplasm. It can be with or without organelles. Cell membrane Cytoplasm Vacuole Cell membrane Mitochondria Chloroplasts. Organelles that are involved in photosynthesis. Cell wall . It surrounds the cell and keeps its shape. Nucleus Cytoplasm Organelles Organelles Nucleus Genetic material . It is dispersed in the cytoplasm. Cell wall . It is a rigid cover around the cell membrane. It protects the cell and keeps its shape. Eukar yotic animal cells Cells have a spherical or an irregular shape. The nucleus is located in the centre. They do not have a cell wall . They do not have chloroplasts. Eukar yotic plant cells Cells have a prism shape. The nucleus is pushed to one side of the cell by large organelles called vacuoles. They have a cell wall . They have chloroplasts. Plant cells seen through a microscope Animal cells seen through a microscope Genetic material . It is formed of a type of nucleic acid called DNA. It contains instructions that help the cell to function correctly. It also passes genetic information on to new cells that are created through reproduction . Cell membrane. A thin layer that covers the cell . It regulates the passing of substances into and out of the cell . Cytoplasm. A jelly-like f luid , made of water and many dissolved substances. It contains organelles or complex structures that have dif ferent functions. Bacterium seen through a microscope CHALLENGE 77 76 ES0000000100241 959327_Unidad04_104476.indd 76-77 28/12/21 8:58 4 5. The five kingdoms 22 WORK WITH THE IMAGE. Look at the photo and answer the questions: a) What does the picture show? b) What living things are there in this product? 23 Plants, algae, and some bacteria share one characteristic that is very important for all living things. What is this characteristic? Why it is important? 24 As well as animals and plants, there are other important living things. They are grouped into three kingdoms. Answer these questions to complete the challenge: a) What are the other kingdoms called? b) Identify a living thing from each of those kingdoms that is useful for humans in different areas, such as health, food, industry, etc. 25 What are yeasts? Find out about one type of yeast. Give its scientific name and explain why it is useful. All living things, from tiny bacteria to ver y large whales, are classified into five kingdoms: Animal kingdom Vertebrates and invertebrates belong to this kingdom. Nutrition : heterotrophic Cell type: eukar yotic Organisation : multicellular, with tissues Mobility : most are mobile Plant kingdom Fungi kingdom Protoctist kingdom Monera kingdom Includes mosses, ferns and f lowering plants. Nutrition : autotrophic Cell type: eukar yotic Organisation : multicellular, with tissues Mobility : immobile Includes yeasts, moulds and fungi . Nutrition : heterotrophs Cell type: eukar yotic Organisation : unicellular or multicellular, without tissues Mobility : immobile This kingdom includes protozoa and algae. Nutrition : autotrophic or heterotrophic Cell type: eukar yotic Organisation : unicellular or multicellular, without tissues Mobility : mobile or immobile This is the bacteria kingdom. Nutrition : autotrophic or heterotrophic Cell type: prokar yotic Organisation : unicellular Mobility : mobile or immobile Biodiversity Biodiversity is all the living things that live in a specific place, countr y or within the biosphere. Nobody knows the exact number of species that inhabit the Earth . Scientists have identified around 1.5 million species. Bacteria , from the Monera kingdom, are not included in these figures because scientists do not know how to count them. In the Fungi and Protoctist kingdoms there are more unknown species than those that are known. CHALLENGE Insects 840 000 Molluscs 70 000 Fungi 70 000 Protoctists 80 000 Vertebrates 46 500 Other arthropods 80 000 Flowering plants 230 000 Mosses and ferns 26 500 Other invertebrates 80 000 87 86 ES0000000100241 959327_Unidad04_104476.indd 87 28/12/21 8:58 ESSENTIAL KNOWLEDGE 4 CORE SKILLS 3
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