Q.  6.  What are the characteristic features of a true-breeding line?

True breeding is a stable trait inheritance and expression for several generations as a result of continuous self-pollination.

Characteristic features of a true-breeding line

(i)  They are used as parents in artificial hybridization as they provide gametes with all similar traits.

(ii)  Homozygous recessive plants are used in the test cross to determine the genotype.