Q34 of 58 Page 69

Give two reasons for the appearance of variations among the progeny formed by sexual reproduction.

Two reasons for the appearance of variations among the progeny formed by sexual reproduction are mentioned below-


(i) The progeny formed from sexual reproduction involves two parents with different sets of characters.


(ii) The genetic material is exchanged between chromosomes before forming of zygote. Deoxyribonucleic acid (DNA) exchange in the chromosome. This results in forming of variation in the progeny.


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From the internet, gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions.

(a) Do larger organisms have more number of chromosomes/cells?


(b) Can organism with fewer chromosomes reproduce more easily than organisms with more number of chromosomes?


(c) More the of chromosomes/cells greater is the DNA content. Justify.