Question

Which of the following statements is true for variation in organisms?
(P) The occurrence of differences among the individuals of the same species is known as variation.
(Q) Variations decrease the possibilities of survival.
(R) The process of evolution decreases the variation in organisms.
(S) During meiosis, crossing over takes place between the genes and hence, combinations are formed, which ultimately results in producing variations.
A. (P) and (S)
B. (Q) and (S)
C. (P) and (R)
D. (Q) and (P)

Answer 1

Variation may be due to inherited or environmental elements. Variations may be non-stop or discontinuous. Variation between distinctive species is typically more than the variant inside a species.

Complete Answer:
To answer this question, first, we need to know about the variation. Variation is any distinctive among cells, single organisms, or units of organisms of any species triggered both with the aid of using genetic variations (genotypic variant) or by the impact of environmental elements at the expression of the genetic potentials (phenotypic variant). Variation can be proven in external appearance, metabolism, fertility, mode of reproduction, behaviour and intellectual ability, and different apparent or measurable characters.

Now, let us find the solution from the option.
- Variations are the motives why members of the similar species are distinguishable from one another. It additionally will increase the chance of survival as greater adventitious versions collect within the species and assist in the system of evolution.
- During the time of gamete generation, in meiosis, exchanging of genetic material occurs and genes are exchanged that causes different versions in organisms.
- Genotypic variants are the result of differences in range or shape of chromosomes or with the aid of using variations within genes carried via the chromosomes. Eye colour, structure of body, and preventing diseases are genotypic variants.

Thus, the correct option is A. i.e. (P) and (S).

Note: Environmentally triggered variants may be caused by one element or the together effects of many factors, like climate, meal supply, and functioning of different organisms. Phenotypic versions additionally involve phases in an organism’s existence cycle and seasonal variations in an individual. These versions do now no longer contain any hereditary alteration and usually are not transmitted to next generations; consequently, they are now no considerable in the manner of evolution.