Genetics And Plant Breeding - Study Mode
[#921] Endosmosis occurs when a plant cell is put in
Correct Answer
(D) Hypotonic solution
Explanation
Solution: Endosmosis occurs when a plant cell is put in a hypotonic solution. Endosmosis is the movement of molecules from a region of high concentration to a region of low concentration through a semi-permeable membrane. A hypotonic solution is a solution with less amount of solute in comparison with the other solution. Therefore when a plant cell is put under hypotonic solution, the movement of molecules starts from the solution to the plant cell, which in turn leads to endosmosis.
[#922] Progeny of a F 1 hybdrid plant
Correct Answer
(D) Segreagates in next generation
Explanation
Solution: The progeny of an F 1 hybrid plant Segregates in the next generation. An F 1 hybrid is a term used in genetics and selective breeding. F 1 stands for Filial 1, the first filial generation seeds/plants or animal offspring resulting from a cross-mating of distinctly different parental types. The characters further segregate into the next generation. Crossing two genetically different plants produce hybrid seed. For mass production of F 1 hybrids with uniform phenotype, the parent plants must have predictable genetic effects on the offspring.
[#923] How many pairs of contrasting characters were studied by Mendel?
Correct Answer
(B) 7
Explanation
Solution: Seven pairs of contrasting characters were studied by Mendel as follows: • Pea shape (round or wrinkled) • Pea color (green or yellow) • Pod shape (constricted or inflated) • Pod color (green or yellow) • Flower color (purple or white) • Plant size (tall or dwarf) • Position of flowers (axial or terminal)
[#924] Which of the following part of the plant should be excluded for the study of Viral effects?
Correct Answer
(B) Shoot apex
Explanation
Solution: Shoot apex is the part of the plant that should be excluded from the study of Viral effects. The shoot apex is the growing tip of the plant shoot and has a crucial role in morphogenesis, this is where new leaves or flowers emerge and rapidly expand. The apex meristem maintains a balance between the self-renewal of a reservoir of central stem cells and organ initiation from peripheral cells. Since these cells have very high metabolic rates, it is difficult for the cells to be used for viral studies.
[#925] A Chromosome with centromere at one end is termed as
Correct Answer
(C) Telocentric
Explanation
Solution: A Chromosome with a centromere at one end is termed Telocentric. Telocentric chromosomes have a centromere at one end of the chromosome and therefore exhibit only one arm at the cytological level. They are not present in humans but can form through cellular chromosomal errors. Telocentric chromosomes occur naturally in many species, such as the house mouse, in which all chromosomes except the Y are telocentric.