Genetics And Plant Breeding - Study Mode
[#501] Bread wheat is
Correct Answer
(D) Auto-allopolyploid
Explanation
Solution: Bread wheat is Auto-allopolyploid. Autoallopolyploid, is having one set of chromosomes (or one genome) in a more than diploid state. Bread Wheat (Decaploid triticale) (AABBDDRRRR) is an example of auto-allopolyploidy. This plant has two copies of each of the three genomes of bread wheat (ABD) and four copies of that of rye genome (R). Thus the rye genome is in autotetraploid condition.
[#502] The longest phase in cell cycle is
Correct Answer
(A) Prophase
Explanation
Solution: The longest phase in the cell cycle prophase, from the given options. The first and longest phase of mitosis is prophase. During prophase, chromatin condenses into chromosomes, and the nuclear envelope (the membrane surrounding the nucleus) breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles of the cell.
[#503] D-genome of common cultivated wheat has been contributed by
Correct Answer
(D) Ae squarosa
Explanation
Solution: D-genome of common cultivated wheat has been contributed by Ae squarosa . The D genome of allohexaploid bread wheat (Triticum aestivum, 2n = AABBDD) is the least diverse of the three wheat genomes and is unarguably less diverse than that of diploid progenitor Aegilops tauschii (2n = DD). Aegilops tauschii (synonyms Aegilops squarrosa, Triticum tauschii), is a wild goatgrass that was one of the parent species of bread wheat.
[#504] Two taxonomic species are distinguished from each other by
Correct Answer
(A) Their failure to interbreed
Explanation
Solution: Two taxonomic species are distinguished from each other by their failure to interbreed. Interbreed is the act of mixing different species or varieties of animals or plants and thus producing hybrids. An ancestral species is split into two or more descendant species that are genetically different from one another and can no longer interbreed.
[#505] The distribution of stomata per unit area of a leaf and their size affects the rate of
Correct Answer
(C) Transpiration
Explanation
Solution: The distribution of stomata per unit area of a leaf and their size affects the rate of Transpiration. Transpiration is a process that involves the loss of water vapour through the stomata of plants. The loss of water vapour from the plant cools the plant down when the weather is very hot, and water from the stem and roots moves upwards or is 'pulled' into the leaves. Transpiration is closely related to stomata. Nearly 97% of the water from plants is lost through stomatal transpiration, so the more stomata, the higher the transpiration rate.