Question

Describe the importance of variation.

Answer 1

Hint: Variation is any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences or by the effect of environmental factors on the expression of genotypic character.

Complete answer:
Importance of Variation is as follows –
1. Variations make some individuals better suited in the struggle for existence.
2. They help individuals to adapt themselves to the changing environment.
3. Discontinuous variations produce new traits in the organisms.
4. Variations allow breeders to improve races of useful plants and animals for increased resistance, better yield, quicker growth, and lesser input.
5. They constitute the raw material for evolution.
6. Variations give each organism a distinct individuality.
7. Because of variations, species do not remain static. Instead, they are slowly getting modified, forming new species with time.
8. Pre-adaptations caused by the presence of neutral variations are extremely useful for survival against sudden changes in the environment, e.g., resistance against a new pesticide or antibiotic.

DNA mutation causes genetic variation by altering the genes of individuals in a population. Examples of genetic variation include eye colour, blood type, camouflage in animals, leaf modification in plants, etc.
Some causes of variation can be by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

Note: Variation in a species is not uncommon, but there are actually two major categories of variation in a species:
1. Continuous variation- It is where different types of variations are at continuity. For example, hair colour, etc.
2. Discontinuous variation- It occurs when different types of variation are qualitatively discrete. For example, the blood group has limited (discrete) variations.