Genetics And Plant Breeding - Study Mode
[#491] Self-incompatibility was first reported by
Correct Answer
(A) Koelreuter
Explanation
Solution: Self-incompatibility was first reported by Koelreuter. Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms and thus encourage outcrossing and allogamy. Self- incompatibility was first reported by Koelreuter in the middle of the eighteenth century. It has been extensively studied in different plant families after the first discussion on self-incompatibility by Darwin (1877). The term self-incompatibility is given by Stout in 1917.
[#492] When the pollen from one plant falls on the stigma of other flower of the same plant is
Correct Answer
(B) Geitonogamy
Explanation
Solution: When the pollen from one plant falls on the stigma of another flower of the same plant is Geitonogamy. Geitonogamy is when pollen is exported using a vector (pollinator or wind) out of one flower but only to another flower on the same plant. It is a form of self-fertilization. In flowering plants, pollen is transferred from one flower to another flower on the same plant, and in animal-pollinated systems, this is accomplished by a pollinator visiting multiple flowers on the same plant.
[#493] In tobacco, Nicotiana dighila has originated from a cross between
Correct Answer
(B) N. tabacum and N. glutinosa
Explanation
Solution: In tobacco, Nicotiana dighila originated from a cross between N. tabacum and N. glutinosa. tobacco plants are cultivated as ornamental garden plants. N. tabacum is grown worldwide for the cultivation of tobacco leaves used for manufacturing and producing tobacco products. Nicotiana tabacum, or cultivated tobacco, is an annually grown herbaceous plant of the Nicotiana genus. N. glutinosa is a Dicotyledon and is from the family of Solanaceae. The use of N. glutinosa in tobamoviruses allowed for the death of lesions within the plant.
[#494] The cell of embryosac which releases one chemical to guide the movement of pollen towards ovule is
Correct Answer
(A) Synergid
Explanation
Solution: The cell of embryosac which releases one chemical to guide the movement of pollen towards the ovule is Synergids. Synergid cells are two specialized cells that lie adjacent to the egg cell in the female gametophyte of angiosperms and play an essential role in pollen tube guidance and function. Defensin-like polypeptide LUREs are pollen tube attractants secreted from synergid cells.
[#495] Ganga-4 is a
Correct Answer
(B) Double cross hybrid
Explanation
Solution: Ganga-4 is a Double cross hybrid . It is a cross-product of CM 400 × CM 300 × CM 602. Matures in 100 - 105 days. Plants have medium-thick stems with long narrow green leaves. This cultivar also possesses moderate resistance to downey mildew, leaf blight, rust stem borer and lodging. Suitable for all maize growing areas.