Genetics And Plant Breeding - Study Mode
[#421] A genophore is made up of
Correct Answer
(B) ss or dsDNA
Explanation
Solution: A genophore is made up of ss or dsDNA. A genophore is the DNA of a prokaryote. It is commonly referred to as a prokaryotic chromosome. It is made up of single or double stranded circular supercoiled DNA.
[#422] If a female plant of genetic constitution AABB is crossed to a male plant of genetic constitution aabb and the F 1 is test crossed, the genetic constitution of the test crossed progenies will be
Correct Answer
(D) 1AaBb : 1Aabb : 1aaBb : 1aabb
Explanation
Solution: If a female plant of genetic constitution AABB is crossed to a male plant of genetic constitution aabb and the F 1 is test crossed, the genetic constitution of the test crossed progenies will be 1AaBb : 1Aabb : 1aaBb : 1aabb. Under the law of dominance in genetics, an individual expressing a dominant phenotype could contain either two copies of the dominant allele (homozygous dominant) or one copy of each dominant and recessive allele (heterozygous dominant). By performing a test cross, one can determine whether the individual is heterozygous or homozygous dominant. The test cross ratio obtained by crossing AABB X aabb will be 1 : 1 : 1 : 1.
[#423] Which hormone suppresses the growth of plant?
Correct Answer
(B) Abscisic acid
Explanation
Solution: Abscisic acid hormone suppresses the growth of the plant. Abscisic acid (ABA) is a plant hormone that regulates numerous aspects of plant growth, development, and stress responses. Seed germination is inhibited by ABA in antagonism with gibberellin. ABA also prevents the loss of seed dormancy. Abscisic acid is also produced in the roots in response to decreased soil water potential and other situations in which the plant may be under stress.
[#424] The sources of male sterility include
Correct Answer
(D) None of these
Explanation
Solution: The sources of male sterility include failure of another dehiscence, nonfunctional pollen grains, etc. But it is not caused by Spontaneous mutations, Induced mutations, and Interspecific crosses. Male sterility (CMS), a condition under which a plant is unable to produce functional pollen, is widespread among higher plants. Male-sterility plants provide crucial breeding tools to harness hybrid vigor, or heterosis, in hybrid crops and also provide important materials to study stamen and pollen development and cytoplasmic-nuclear genomic interactions.
[#425] What happens in PS-II?
Correct Answer
(A) Photolysis of water
Explanation
Solution: Photolysis of water happens in PS-II. Photosystem II is the first protein complex in the light-dependent reactions of oxygenic photosynthesis. Within the photosystem, enzymes capture photons of light to energize electrons, and these energized electrons are replaced by oxidizing water to form hydrogen ions and molecular oxygen. That is photolysis means the breakdown of water in the presence of light.