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Heredity and Evolution — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10ScienceHeredity and Evolution3 Marks
Question
Explain how the variations get accumulated.
✓

Answer

The accumulation is the variations of gradual changes which takes places in primitive organisms over millions of years and new organisms are formed.
There are four ways in which this can do. These are:
  1. Natural selection: Those variations which give survival advantage to an organism are selected in nature and such traits increase in population.
  2. Genetic drift: It occurs due to change in gene frequency due to accumulation of particular type of genes.
  3. Geographical isolation: It leads to change in gene frequency leading to expression of one type of traits in a geographically isolated population.
  4. DNA changes: Variations during DNA copying often leads to the formation of a new species.

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