Question

Which is a similar term to Hybrid vigour?
a. Heterosis
b. Homozygosity
c. Heterozygosity
d. Homosis

Answer 1

Hint: Inbreeding is a mating between individuals that are closely related through common ancestry. One consequence of inbreeding is an increased chance that an individual will be homozygous for a recessive harmful allele. This result is reduced fitness and lower survival rates among inbred populations. The number of harmful alleles present in the gene pool of a population is referred to as the genetic load. This phenomenon is called Heterosis (Hybrid vigor).

Complete answer:
> Option A: Heterosis:
It is also known as Hybrid vigor. Heterosis is a phenomenon of crossing between two individuals to show qualities which are superior to those of both parents. G.H. Shull coined the term heterosis. Heterosis increases the characteristics of the organisms such as size, growth rate, fertility, and yield over the parent generation.

> Option B: Homozygosity:
The crossing over of two individuals of the same allele of a specific gene is called homozygous. This results in homozygosity.

> Option C: Heterozygosity:
The crossing over of two individuals of a different allele of a specific gene is called heterozygous. This results in heterozygosity.

> Option D: Homosis:
It is a phenomenon of crossing between two individuals to show qualities which are inferior to those of both parents.

Hence, the correct answer is option (A).

Note: Heterosis is the improved function of a biological quality in a hybrid offspring. Heterosis is due to Mendelian or non-Mendelian inheritance. All the outcrosses do not result in heterosis. Parents are not fully compatible with hybrid inherits, fitness can be reduced. This phenomenon forms an outbreeding depression.