Genetics And Plant Breeding - Study Mode
[#486] When embryo originates from unfertilized egg, is known as
Correct Answer
(A) Parthenogenesis
Explanation
Solution: When an embryo originates from an unfertilized egg, is known as Parthenogenesis. It is a natural form of asexual reproduction in which the growth and development of embryos occur in a gamete (egg or sperm) without combining with another gamete. In plants, parthenogenesis is a component process of apomixis. In algae, parthenogenesis can mean the development of an embryo from either an individual sperm or an individual egg.
[#487] In mutation breeding programme the mutant population can be selected in which generation?
Correct Answer
(B) F2
Explanation
Solution: In the mutation breeding programme, the mutant population can be selected in the F2 generation. Mutation breeding refers to the method of using artificial mutagenesis to obtain new biological cultivars, mainly through chemical or radiation mutagenesis. In order to generate mutants with desirable traits to be bred with other cultivars. Plants created using mutagenesis are sometimes called mutagenic plants or mutagenic seeds.
[#488] Pure line is
Correct Answer
(A) The progeny of selfed homozygous plant
Explanation
Solution: The pure line is the progeny of a selfed homozygous plant. The pure line is the progeny of a single self-fertilized homozygous plant. The concept of pure line was proposed by Johannsen on the basis of the studies with beans variety. He obtained the seeds from the market and observed that the lot consisted of larger as well as smaller seeds. Progeny of larger seeds produced larger seeds and the progenies of smaller seeds produced small seeds only.
[#489] Over time there is loss in vigour and productivity of clones. The phenomenon is known as
Correct Answer
(C) Clonal degeneration
Explanation
Solution: Over time there is a loss in vigour and productivity of clones. The phenomenon is known as Clonal degeneration. The loss in vigour and productivity of clones with time is known as clonal degeneration and it may be due to mutation and infection of viruses and bacteria. It is when cannabis clones lose their uniqueness in producing certain properties or compounds, including cannabinoids and terpenes.
[#490] For vigour test Paper piercing method was proposed by
Correct Answer
(A) Fritz, 1965
Explanation
Solution: For vigour test, the Paper piercing method was proposed by Fritz, in 1965. Seed vigour is an important quality parameter that needs to be assessed to supplement germination and viability tests to gain insight into the performance of a seed lot in the field or storage. The principle of the paper piercing test is similar to that of the brick gravel test. High vigour seed lots are expected to produce strong seedlings which can pierce a particular type of paper while seedlings of poor vigour lots may not be able to pierce the paper. Therefore, the seedlings which emerge by piercing the paper.