LOSSES OF BIODIVERSITY

Extinction is a fact of life. Species have been evolving and dying out ever since the origin of life. One only has to look at the fossil record to appreciate this. It has been estimated that surviving species constitute about 1% of the species that have ever lived.

However, species are now becoming extinct at an alarming rate, almost entirely as a direct result of human activities. Previous mass extinctions evident in the geological record are thought to have been brought about mainly by massive climatic or environmental shifts. Mass extinctions as a direct consequence of the activities of a single species are unprecedented in geological history. The loss of species in tropical ecosystems such as the rain forests, is extremely well-publicised and of great concern. However, equally worrying is the loss of habitat and species closer to home.

● How do you pronounce: origin, appreciate, entirely, direct, previous, evident, geological?

● What part of speech is record? What syllable is stressed?

● Which words in the text have the same meaning as: very, completely, early, not far, frightening, in most cases?

● Are the words evolve and develop synonyms or opposites?

● To die out is a phrasal verb meaning to disappear completely. What part of speech is dying out?

● Does unprecedented mean often having happened before or never having happened before?

● Does rate mean level or speed?

● Explain the words: to survive, fossil, shift, concern, habitat.

● However is a compound word. Find other compounds in the text.

● What is the difference between to appreciate and to estimate?

● Fill in the chart with the family words and translate them. Use a dictionary if necessary.

6.4. The formation of plural nouns may be different. Study some of them below and fill the gaps in the sentences, choosing the correct form.

1. The …….. was based on …….. collected in the field.

2. …….. with little genetic diversity have limited ability to adaptation.

3. Darvin offered a working …….. for the mechanism of evolution.

4. Some types of …….. cause disease.

5. A Leopold’s work forms the …….. of modern environmental ethics.

6. A period of economic …….. is difficult for any country.

7. Last year he wrote a doctoral …….. .

8. An animal with …….. is called a vertebrate.

6.5. Are these statements true (T) or false (F)?

1. Large carnivoures are at the top of food chains.

2. Fish are cold-blooded vertebrates.

3. Frogs are amphibians and they live only on land.

4. Dinosaurs were reptiles.

5. Birds have feathers and wings and lay eggs.

6. Mammals are warm-blooded vertebrates without hair.

7. Algae are very simple plants with roots and leaves.

8. Mushrooms refer to fungi.

9. Mosses grow close to the ground in wet areas.

10. Ferns don’t have flowers.

6.6. Classify the following animals as either carnivores or herbivores.

cow / rabbit / dog / shark / deer / lion / eagle / giraffe / seal / grass snake / horse

6.7. Classify the following as producers, primary consumers or secondary consumers.

caterpillar / falcon / mouse / tree / phytoplankton / pike / cat / grass / locust / goat / otter / wheat

6.8. Fill in the gaps with the word(s) from the box:

In a food chain, …….. passes from one …….. to another. The …….. of the …….. is always less than that of the …….. because most of the food eaten by the …….. is used to produce …….. rather than new growth.

6.9. Distinguish between the terms ‘pesticide’, ‘insecticide’ and ‘herbicide’. Put the following events in the most probable order.

1. Predatory birds poisoned by insecticide.

2. Trees sprayed with insecticide.

3. Earthworms eat leaves which fall from trees.

4. Predatory birds eat small birds.

5. Beetles damage trees by spreading a virus.

6. Insecticide absorbed by tree leaves.

7. Small birds eat earthworms.

6.10. Choose the correct item.

1. Zoologists work hard to …….. endangered species.

a) protect b) shelter c) cover d) support

2. Greenpeace is going to release a(n) …….. on water pollution.

a) edition b) issue c) publicity d) report

3. The tropical …….. of Africa need to be protected from destruction.

a) regions b) states c) places d) sites

4. To improve the …….. of the water, use a water-purification tablet.

a) standard b) amount c) quantity d) quality

5. Acid rain has caused a lot of …….. to Europe’s trees.

a) wreck b) ruin c) damage d) disaster

6. Five world leaders are due to attend the …….. meeting in London.

a) tip b) top c) summit d) peak

7. Trees and vegetation help …….. a healthy climate locally and globally by absorbing pollutants and greenhouse gases.

a) follow b) ensure c) entail d) enlarge

8. Biogeography studies the …….. distribution of organisms on the Earth.

a) environmental b) various c) spatial d) vital

9. Flowering plants reproduce themselves from …….. .

a) stems b) pistils c) buds d) seeds

10. Parkland and gardens are two examples of …….. ecosystems.

a) artificial b) natural c) marine d) sensitive

6.11. Which of the following are likely to help conserve soil and prevent erosion? Fill in the table.

6.12. Fill in the gaps with the word from the box:

I loved the old oak treeу in our garden, especially the sound of the …….. rustling in the breeze. I remember standing, pressed against the …….. , trying to embrace the huge …….. , but not being able to. Once while climbing it, a …….. snapped off beneath my feet, but luckily wasn’t hurt. We used to love swinging on the …….. . When I was a child, I used to imagine that the …….. reached right down to Australia.

6.13. Fill in the gaps with the word from the box:

My aunt Mary has a beautiful parrot called Percy. He has brightly coloured …….. and sharp …….. . When you open the door of his golden …….. , he comes out, spreads his …….. and flies round the room. You have to be careful not to put your fingers too near him because he may …….. at them. Percy enjoys eating sunflower seeds with his hooked …….. , and wakes my aunt up every morning with his continuous squawking.

6.14. Fill in the correct word derived from the word in bold.

6.15. Biology has many branches, for example, Anatomy, Biochemistry, etc. Match the branches with their definitions.

6.16. Read the text Ecology: Organisms and Their Interaction and do the exercises after it.

Date: 2016-04-22; view: 1585