Question

Pure line breed refers to
A. Homozygosity
B. Heterozygosity
C. Homozygosity with only dominant genes
D. Heterozygosity and linkage

Answer 1

Hint: A group of identical individuals that always produce offspring of the same phenotype in the pure line breeding. And the process of pure line breed occurs when they are homozygous. And because of the homozygosity which produces offspring of only one type. It is the true breeding of genotypes in which all the homozygous genes under the successive consideration and produced only homozygous offspring.

Complete answer:
Self-fertilization in which the plants produced the same traits process known as true breeding. This process is similar, homozygous and produces offspring of its own and are genetically identical. Botany is the branch of science in which true plant breeding occurred and helped to improve the agricultural crops. Plant breeding was introduced by Riley in 1978 and then modified by Frankel in 1958 by experiment on the genetic adjustment of the plants. Genotype that is present in the plants change with the help of true breeding. Inheritance principle also known by the help of plant breeding and considered as a current phase of crop evolution.
The prime aim of the plant breeding is to improve the crop quality by using the methods such as improved quality, disease and preset resistance, higher yields, dormancy, moisture stressed salt tolerance and determine the growth habit. In 1963 ICAR was introduced with the production of dwarf and semi dwarf cereal varieties and also nebulization of the sugarcane, also helped to modify the transgenic plants by using some techniques from genetic engineering.

Therefore the correct option is (A).

Note: Same phenotype is a process in which parents produce the same offspring known as true breeding. True breeding means parents are homozygous for every trait. In the pure breeding that occurred in the plants having either recessive or dominant alleles of a gene. Due to the presence of both types of same allele pure breeding produce the progeny of their own kind in the plant.