IGCSE Biology 2nd edition GCSE Biology 3rd 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 30. Classification


Page 269
1. a Many cells. Plants, Animals
    b Nuclei. Protoctista, Fungi, Plants, Animals.
    c Cell walls. Plants.
    d Hyphae. Fungi.
    e Chloroplasts. Plants, some Protoctista.

Page 276
1. Snails and earthworms are primary consumers but earthworms may play a part as decomposers. They are both eaten by secondary consumers, e.g. birds.
2. Withdrawal into their burrows and retraction into their shells protects earthworms and snails from predators and desiccation.
3. At low temperatures the chemical reactions in cells slow down and this affects the whole animal and particularly movement.

Page 278
1. a Warm-blooded. Birds, mammals.
    b Four legs. Amphibia, Reptiles, Mammals.
    c Lay eggs. Fish, Amphibia, Reptiles, Birds.
    d Internal fertilisation. Reptiles, Birds, Mammals.
    e Parental care. Reptiles, Birds, Mammals.
2. This is an unfair question. The text does not give criteria for all the groups listed on p.274 and it is not feasible to construct a dichotomous key for the whole animal kingdom.

Page 281 (Left hand column)
1. Beetle. Animal, arthropod, insect.
    Sparrow. Animal, vertebrate, bird.
    Weasel. Animal, vertebrate, mammal, (carnivore).
    Gorilla. Animal, vertebrate, mammal, (primate).
    Pine tree. Plant, vascular plant, conifer.
    Buttercup. Plant, vascular plant, flowering plant (dicotyledon).
    Moss. Plant, bryophyte, moss.
2. Although both plants are in the same genus (Lamium), they are different species (album and purpureum) so you would not expect them to cross-pollinate successfully.
3. Bracken propagates vegetatively by means of underground rhizomes (p.79) which are too deep in the soil to be affected by fire.
4. Trees, shrubs and ‘flowers’ are vascular plants. They are so called because they have well developed vascular systems consisting of xylem and phloem (pp 54-6).

Page 281 (Right hand column)
1.
   1. Flagella or cilia present … 2
       No flagella or cilia …… … Amoeba
   2  Flagella present ………… 3
       Cilia present … … ……… 4
   3. Two flagella… … … … … Chlamydomonas
       One flagellum………… … Euglena
   4. Stalk present … ………… Vorticella
       No stalk … …………… … Paramecium

2.
    1. Yellow flowers ……………………… 2
         Flowers not yellow ………………… 3
    2. Large flowers on individual stalks … daffodil
        Small flowers on a prickly bush …… gorse
    3. Flowers green ……………………… couch grass
        Flowers not green … … …………… 4
     4 Flowers white …………………….… snowdrop
        Flowers; a range of colours … … … lupin
This is an ‘artificial’ key because it depends not on genuine classificatory data but on a superficial characteristic, in this case, colour.

3.
    1. Little or no vascular tissue present …… 2
        Vascular tissue present………………… 3
    2. Flat leaflike form … … … … … … … … Liverworts
        Vertical stem with small leaves…………Mosses
    3. Reproduce by spores … … …………… Ferns
        Reproduce by seeds … … … ………… 4
    4 Seeds not enclosed in fruit … … ……… Conifers
       Seeds enclosed in fruits………………… 5
    5 Seeds with one cotyledon ……………… Monocotyledons
       Seeds with two cotyledons ….. …………Dicotyledons

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

© Copyright 2004 - 2017 D G Mackean & Ian Mackean. All rights reserved.