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71. Describe De Vries Mutation theory.

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72. What is the main difference between Darwin's theory of natural selection and De Vries mutation theory ?

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73. What is competition in nature ? How does it affect the plant and animal life ? Mention some examples.

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74. Where did Darwin err in his theory of the “Origin of Species” through natural selection ?

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75. List three mechanisms by which variant genotypes can be produced in nature.

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76. Why is the frequency of sickle cell anaemia more in the malaria prone areas ?

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77. What is industrial melanism ?

Explain how natural selection has worked on population of peppered moth in industrial area of England.

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78. What observations is natural selection based on ?

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Differences between artificial selection and natural selection

Artificial selection

Natural selection

1. It is selection by man.

2. Variants suited to human requirement are selected by man

1. In it, the selection is through nature.

2. Variants adapted to the environment are able to thrive better.

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80. Polyploidy can also lead to the formation of a new species very rapidly. Explain.

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