(a) What do you understand by the term 'variation'?
(b) Name two human traits which show variation.
(c) How does the creation of variation in a species ensure its survival?
Answers
Explanation:
Variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation).
Almost all the human traits show variation. Variations occur in the generations of sexually reproducing organisms. The two human traits that show variation are as follows :
i) Ear lobes: free and attahed earlobes, is closely attached to the side of the head in some of us and not in others.Free and attached are two variants found in human being.
ii) Eye color : from black to brown to blue to hazel brown, there are so many shades of eye colours found in the human population.
Explanation:
Variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation).
Variation simply means difference. It could be the difference in cells, tissues, organs, or even organisms. This variation could be attributed to both genetic factors as well as some environmental factors. For example, the human eye color and skin color show variation as they are polygenic traits, meaning, they are influenced by a number of genes in combination with various environmental factors, including the temperature, and humidity of the area that they reside in
Different individuals have different chances. Selection of variants by environmental factors forms the basis for evolutionary processes. These variations may lead to increased survival advantages of the individuals due to positive adoption of traits or may merely contribute to the genetic drift.