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1. Variation 1 Within a species there is usually a great deal of variation between individuals

2. 7 What variations can you see ? There are variations in skin colour, hair colour, hair curliness, eye colour and sex Human variations

4. 9 Acquired characteristics result from an individual’s activities or nutrition or from environmental conditions during a lifetime Examples of acquired conditions in humans are* -language -obesity -athletic skills -mental skills -body building -sun tan -Acquired characteristics cannot be inherited Acquired characteristics

5. 10 -The next side shows apples collected from different positions on the same tree -The differences between the apples are acquired during the growing season -The differences will not be inherited

6. 11 North side, upper branches South side upper branches South side, lower branches North side, lower branches © Horticultural Research International Apples

10. Your ABO blood group is either A, B, AB or O

12. 15 percentage in population of Britain Discontinuous variation in blood group. The figures cannot be made to fit a smooth curve because there are no intermediates Blood groups

13. 16 Continuous variation -Continuous variation is influenced by genes and environment, resulting in a range of phenotypes between two extremes, e.g. height in humans. -For example, there is every shade of hair colour between black and blond. People do not belong to one or other of a small number of distinct categories. -Variations such as these are under genetic control but there are several pairs of genes involved. -The genome AA BB CC DD might give black hair while the genome aa bb cc dd might give blond hair.* -Genomes AaBbCcDd or AABbCCdd or aaBBccDd and all the other possible combinations would give intermediate colours

14. 17 There are as many categories of hair colour as there are children Hair colour variation

15. 18 Continuous variation also occurs when the characteristics are controlled by the genesand the environment -Your height will depend on the genes you inherit and on the amount of food you eat during your growing period The next slide shows the range of heights of army recruits Continuous variation

16. 19 thousands of men height in inches There seem to be distinct categories of height but this is because measurements are made to the nearest inch Graph of heights

17. 20 If measurements could be made to the nearest millimetre there would be a smooth transition in the heights

18. 21 This is how continuous variation would appear in a graph

19. 22 Question 1 Which of these statements are correct? (a) Wild plants of the same species do not vary (b) There is always variation between individuals of the same species (c) Individuals in the same species may show variations (d) Daschunds and greyhounds are varieties of the same species

20. 23 Question 2 Variations in an individual’s weight… (a) are entirely genetically controlled (b) result exclusively from the amount of food taken in (c) are the result of food intake and genes (d) are the result of chance

21. 24 Question 3 Which of the following can be changed by conditions other than genetic? Blood group (b) Weight (c) Physique (d) Finger prints

22. 25 Question 4 Which of the following are acquired characteristics ? Lung cancer (b) Athleticism (c) Curly hair (d) Big feet

23. 26 Question 5 Discontinuous variations are … (a) inherited (b) not inherited (c) a combination of inherited and acquired factors (d) acquired during a lifetime

24. Question 6 27 Which of the following are examples of continuous variation ? (a) Height (b) Weight (c) Sex (d) Intelligence