Question

Change in the number of body parts is called as?
A) Continuous variation
B) Discontinuous variation
C) Substantive variation
D) Meristic variation

Answer 1

Somatogenic variation is due to external influences on the organism. These mutations are not heritable, will not be transmitted to future generations, and disappear with the death of the organism. The germ mutation occurs in the germ cells of organisms, without external influence.

Complete answer:
Continuous variations: They are also called fluctuating variations because they fluctuate on either side (positive or negative) of the species average or average. Continuous change is a typical feature of quantitative characteristics. They show a difference from the average, which is related to the average through a small intermediate form.
Substantive variations: They affect the appearance, including the shape, size, weight and color of a part or whole of the organism, such as height, nose shape, skin color, eye color, hair, finger or toe length, milk, egg production, etc.
Discontinuous changes are huge, obvious changes, including not only digital changes, but also other changes, such as changes in body color, shape, and size.
Meristic variation refers to a change in the number of repeated body parts of an organism.

Thus the correct answer is option ‘D’.

Note: Even in clones and single-egg twins, variations occur. Here, they are caused or caused by mutations. The changes obtained are usually due to environmental influences. They are not inherited. Mutations are sudden or discontinuous heritable variations caused by DNA replication errors.