Genetics And Plant Breeding - Study Mode
[#286] Consider the following statements with regard to the functions of the centromere in the chromosome. 1. Centromeres are the centres of movement of the chromatids or chromosomes during anaphase separation. 2. Acentric chromosomes lack the capacity to segregate in a regular fashion. 3. Crosing-over in one arm of a metacentric chromosome does not affect the crossing over in the arm of the same chromosome. Which of the statements given above are correct?
Correct Answer
(D) 1 and 3
Explanation
Solution: About the functions of the centromere in the chromosome following statements are true. 1. Centromeres are the centers of movement of the chromatids or chromosomes during anaphase separation. 2. Crosing-over in one arm of a metacentric chromosome does not affect the crossing-over in the arm of the same chromosome. The centromere appears as a constricted region of a chromosome and plays a key role in helping the cell divide up its DNA during division. Specifically, it is the region where the cell's spindle fibers attach.
[#287] Inhibitors to cell membrane synthesis are
Correct Answer
(D) All of the above
Explanation
Solution: Inhibitors to cell membrane synthesis are Polymixin, Gramicidin, and Circulin, also Tyrocidin. Polymyxin antibiotics inhibit bacterial membranes after binding to lipopolysaccharides (LPSs), interacting with lipid A of the outer membrane, and acting as a detergent by disrupting the membrane phospholipids, causing cellular permeability and demise. Gramicidin and circulin are antibiotic peptides that can be incorporated into the monolayers of cell membranes. Tyrocidine is a mixture of cyclic decapeptides produced by the bacteria Bacillus brevis found in soil.
[#288] G. J. Mendel was born in the year and place
Correct Answer
(D) 1822, Brunn
Explanation
Solution: G. J. Mendel was born in the year 1822 and place, Brunn. Gregor Johann Mendel, (20 th July 1822 - 6 th January 1884) was a biologist, meteorologist, mathematician, Augustinian friar, and abbot of St. Thomas' Abbey in Brunn, Margraviate of Moravia. Mendel's pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance.
[#289] In apomixis, the progeny closely resembles
Correct Answer
(B) Female parent
Explanation
Solution: In apomixis, the progeny closely resembles the female parent. Apomixis is asexual reproduction without fertilization. The progeny of an apomictic plant is genetically identical to the maternal plant. Multicellular female gamete-producing structure of a flowering plant. Also known as the female gametophyte.
[#290] The chromosomal theory of Heridity explains
Correct Answer
(C) Genes are located on chromosomes and transmitted to the next generation through them
Explanation
Solution: The chromosomal theory of Heredity explains Genes are located on chromosomes and transmitted to the next generation through them. The Boveri-Sutton chromosome theory is a fundamental unifying theory of genetics that identifies chromosomes as the carriers of genetic material. It states simply that chromosomes, which are seen in all dividing cells and pass from one generation to the next, are the basis for all genetic inheritance.