Q11 of 53 Page 1

Explain the terms:

(i) Speciation


(ii) Natural selection

(i) Speciation is defined as the process of development of new species from the existing species.


The various factors which are responsible for Speciation are:


1. Geographical isolation of a population


2. Genetic drift


3. Variations due to natural selection


(ii)Natural selection is defined as the process of species evolution of passing of characteristics which is helpful in survival of individual organism and not passing of characteristics which are not helpful for survival.


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9

(a) List any two characteristics of a good fuel.

(b) What are non-renewable resources of energy?


Give two examples of such resources.

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Explain how equal genetic contribution of male and female parents is ensured in the progeny.

 12

Explain with examples how the following are evidences in favor of evolution in organisms.

(i) Homologous organs


(ii) Analogous organs


(iii) Fossils

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Write one chemical equation to represent each of the following types of reactions of organic substances:

(i) Esterification


(ii) Saponification


(iii) Substitution