Genetics and Plant Breeding

After a cross of round seeded plant with wrinkled seeded plant, F1 produced 50 per cent round seed and 50 per cent wrinkled seeded plant. The cross is test cross, i.e. Rr X rr.

Flower colour in Mirabilis jalapa shows incomplete dominance

Blood group in man is controlled by multiple alleles.

AB blood group in man is an example of codominance.

A cross 'TtRr' with 'ttrr' is test cross and produces TtRr, Ttrr, ttRr, ttrr genotypes in F1.

In epistatic type of inheritance, one gene alters the effect of the other.

In the F2 generation of a dihybrid cross, four phenotypes appear in the ratio 9:3:3:1, if the loci are unlinked.

If there is a lot of distance between two genes, the chance of crossing over is more.

A cross between F1 and homozygous recessive parental combination is called test cross.

AaBb parents produce 25% AB, 25% Ab , 25% aB and 25% ab gametes. Therefore, this is the right option.

If a haemophilic man marries a woman carrier for haemophilia, the possibility that their daughter would be haemophilic is 50%.

Golden rice contains high concentration of vitamin A. This genetically modified rice is capable of producing beta-carotene in the grain, which is a precursor for vitamin A.

Tt X Tt = TT Tt Tt tt

The fruit will be round yellow.

T present in the plant is enough to make it tall. Hence, both TT and Tt plants are tall.