CBSE Notes, Lectures

CBSE - Biology - How do Organisms Reproduce?

How do Organisms Reproduce?

Long Answer Type

Write two points of difference between asexual and sexual types of reproduction. Describe why variations are observed in the offspring formed by sexual reproduction

Asexual reproduction Sexual reproduction
(a) Involves only one parent (i) Often involves two parents
(b) Gametes are not produced (ii) Gametes are produced
(c) No fertilisation and zygote formation (iii) Fertilisaton and zygote formation is observed.
(d) Meiosis does not occur at anytime during reproduction (iv) Meiosis occurs at the time of gamete formation

Variations are observed in the offspring formed by sexual reproduction, because of
following reasons:
• Gene pool is contributed by two parents.
• Crossing over during meiosis results in variations.
• DNA replication also plays some role in variation.

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