Genetics And Plant Breeding - Study Mode
[#216] The example of blending of alleles is paramutation in
Correct Answer
(B) Maize
Explanation
Solution: An example of blending of alleles is paramutation in Maize. A paramutation is an interaction between two alleles at a single locus, whereby one allele induces a heritable change in the other allele. The first formal description of paramutation was given by R. A. Brink at the University of Wisconsin-Madison in the 1950s, who did his work in maize (Zea mays). He noticed that specific weakly expressed alleles of the red1 (r1) locus in maize, which encodes a transcription factor that confers red pigment to corn kernels, can heritably change specific strongly expressed alleles to a weaker expression state.
[#217] In hexaploid wheat the haploid(n) and basic (x) no. of chromosomes are
Correct Answer
(A) n = 21, x = 7
Explanation
Solution: In hexaploid wheat the haploid (n) and basic (x) no. of chromosomes are n = 21, x = 7. Hexaploid wheat possesses 42 chromosomes derived from its three ancestral genomes. The 21 pairs of chromosomes can be further divided into seven groups of six chromosomes (one chromosome pair being derived from each of the three ancestral genomes), based on the similarity of their gene order.
[#218] The seeds don't require certification are
Correct Answer
(A) Breeder seed
Explanation
Solution: The seeds don't require certification are Breeder seed. Breeder seed shall be genetically so pure as to guarantee that in the subsequent generation, certified foundation seed class shall confirm to the prescribed standards of genetic purity. This is hundred percent physical and genetic pure seed for production of foundation seed. A golden yellow colour certificate is issued for this category of seed by the producing breeder.
[#219] The F 2 ratio in complementary gene action is
Correct Answer
(B) 9 : 7
Explanation
Solution: The F2 ratio in complementary gene action is 9 : 7. Complementary gene action is when two different genes work together to contribute to one single trait. These two genes are involved in a specific pathway, like a biochemical reaction, and produce functional products required to produce a certain trait. A dihybrid cross of complementary genes in F2 generation gives phenotypic ratio as 9 : 7.
[#220] Homozygous line developed through repeated selfing in cross pollinated crop is
Correct Answer
(B) Inbred
Explanation
Solution: The homozygous line developed through repeated selfing in cross-pollinated crop is Inbred. An inbred line is the progeny of a single self-pollinated plant. It is the result of repeated selfing as a result all the alleles in an inbred are in the homozygous form. In the Inbred Development Phase, the breeder begins by crossing two plants with different traits, such as yield, size, shape, color, taste, or disease resistance. The objective is to combine valuable traits from each parent to generate and select offspring containing the best characteristics of both parents.