IGCSE Biology 2nd edition

Here you will find the answers to the 'in-text' questions which occur in IGCSE Biology (2nd edition) and GCSE Biology (3rd edition) by D. G. Mackean, published by Hodder Education, London, UK.

Chapters: | Index | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 |

Chapter 27. Conservation


Page 249
1. Extinction can result from excessive hunting, destruction of habitats, introduction of alien species.
2. CITES concentrates on banning trade in endangered species by persuading countries to pass laws forbidding such trade. WWF adopts a variety of strategies for protecting endangered plants and animals. For example they may attempt to prevent excessive hunting, or the destruction of habitats. Both organisations may attempt to get laws passed to restrict human activities which threaten wildlife and both are dedicated to the preservation of biodiversity.
3. a The extinction of certain wild plants may deny us the chance to develop new drugs from their products.
    b If a plant becomes extinct its genes are lost for good. Some of these genes from drought-tolerant plants could have been introduced to crop plants.

Page 251
1. a Biodiversity means the mixture of plant and animal species which comprise a community.
    b Sustainable development means the development of any kind of industry, farming or technology which does not permanently destroy habitats or reduce biodiversity. Felling trees, for example is not sustainable unless new trees are planted at the same rate.
2. An Area of Special Scientific Interest is a naturally occurring environment on privately owned land but governed by rules concerning its maintenance.
  A Nature Reserve is also a natural habitat but managed by an organisation to maintain and possibly improve its community of wildlife.

Page 252
1. Any renewable resource used to produce energy will have come ultimately from a plant source, e.g. firewood, sunflower oil for diesel, sugar cane for ethanol.
The plant source will have depended on photosynthesis for making these products.
2. The energy used to recycle products will be less than the energy needed to produce them in the first place. For example, the energy needed to melt aluminium is less than the energy needed to mine the ore and extract the metal.

Downloads
Download the answers in PDF format below
Section 1, Chapters 1-5
Section 2, Chapters 6-9
Section 3, Chapters 10-12
Section 3, Chapters 13-17
Section 3, Chapters 18-20
Section 4, Chapters 21-24
Section 5, Chapters 25-27
Section 5, Chapters 28-29
Section 6, Chapters 30-34
Section 6, Chapters 35-37
Section 7, Chapters 38-39
Section 8, Chapters 40-41


To contact me please email: DonMackean@biology-resources.com

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