Question

In crop improvement programmes, haploids are of great importance because they?
A) are useful in studies on meiosis.
B) require only about half the amount of chemical fertilizers as compared to diploids
C) give homozygous lines following diploidization.
D) grow better under adverse conditions.

Answer 1

Hint: Plant breeding is a purposeful manipulation of plant species to create desired plant types that are better for suited cultivation, give better yields, and are disease resistant. Conventional plant breeding has been practiced for thousands of years, since the beginning of human civilization.

Complete step-by-step answer:
Haploid plants are of great importance. In the studies on mutations and also for the production of homozygous plants and are needed in large numbers and also used to get pure line breeds. Haploid plants bear the gametic chromosome number of a species and are generally derived from gametophytic tissue that develops the reproductive phase of plants. Gametophytes develop after meiosis in both anthers and ovules. Haploid spores develop into pollen grains, whereas haploid megaspores generate an eight-celled embryo sac bearing the egg cell. The union of haploid cells from male and female upon fertilization produces a zygote that develops into an embryo, restoring the somatic chromosome number of a species.
Meiosis is the reductional division of a cell and haploid cells are produced by meiosis and mostly take place in a diploid cell so haploids are not used in studies of meiosis. Haploids and diploids need almost the same conditions to grow.
Therefore the correct answer is option C.
Note: An interruption in normal sexual development, either natural or induced, causes the microspore or megaspore to undergo mitotic division without fertilization, eventually resulting in the haploid plant. Such extraordinary development of these gametophytic tissues can be induced in plant tissue culture, resulting in androgenesis or gynogenesis of higher plants.