Genetics And Plant Breeding MCQ Question and Answer | Agriculture MCQ Question

Relative Biological Effectiveness (RBE) usually refers to the damage caused by Radiation.
Relative biological effectiveness (RBE) is defined as the ratio of a dose of standard radiation to the dose of test radiation to produce the same biological effects.
RBE is a relative measure of the damage done by a given type of radiation per unit of energy deposited in biological tissues.

a. Enhancement effect is given by Emerson- The Emerson effect is the increase in the rate of photosynthesis after chloroplasts are exposed to the light of wavelength 680 nm (deep red spectrum) and more than 680 nm (far red spectrum).
b. C₃ cycle is given by Calvin- The Calvin cycle, light-independent reactions, of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose.
c. C₄ cycle is given by hatch and slack- C₄ carbon fixation or the Hatch–Slack pathway is one of three known photosynthetic processes of carbon fixation in plants. It owes the name to the 1960's discovery by Marshall Davidson Hatch and Charles Roger Slack that some plants when supplied with ¹⁴CO₂, incorporate the ¹⁴C label into four-carbon molecules first.
d. Two-step photosynthesis is given by Warburg- The Warburg effect is the decrease in the rate of photosynthesis due to high oxygen concentrations. Oxygen is a competitive inhibitor of carbon dioxide fixation by RuBisCO which initiates photosynthesis. Furthermore, oxygen stimulates photorespiration which reduces photosynthetic output. These two mechanisms working together are responsible for the Warburg effect.

The biological fixation of nitrogen is helped by Molybdenum.
Molybdenum (Mo), an essential micronutrient, plays an important role in nitrogen (N) metabolism and protein synthesis in plants.
During symbiotic N fixation, Mo acts as a cofactor for nitrogenase enzymes to catalyze the redox reaction to convert elemental N into ammonium (NH₄⁺) ions.

The process of development of pollen grains in anther of the stamen is Microsporogeneis.
It is the meiotic or reduction division process that produces pollen grains (or microspores) inside the pollen sacs (or microsporangium) of flowering plants.
Microsporogenesis is an important process in plant reproduction, which includes several series of developmental stages from sporogenous cells to microspores.
Any unpredictable disturbance during the meiotic process reduces gamete viability.

The equilibrium in a random mating population is disturbed by the selection, mutation, inbreeding, migration, and genetic drift in the Selection situation the population may regain its original composition.
Natural selection and non-random mating disrupt the Hardy-Weinberg equilibrium because they result in changes in gene frequencies. This occurs because certain alleles help or harm the reproductive success of the organisms that carry them.
Random mating prevents allele frequencies to change, while genetic drift and natural selection do the opposite.

The Father of Hybrid cotton is C. T. Patel.
Chandrakant T. Patel, (11^th July 1917 - 25^th December 1990) was a cotton scientist, who developed the first commercial cotton hybrid, known as Hybrid-4 (Sankar-4), in 1970, which was later cultivated commercially in the states of Gujarat and Maharashtra.
He is known as the Father of Hybrid cotton. He worked at Surat Agricultural University and after two decades of continuous research efforts, successfully developed an intraspecific hybrid by crossing the Gujarat-67 X American Nectariless variety, known as Hybrid-4 (H-4).

Concerning the domestication of crop plants, both statements are correct.
1. Under domestication, the variability generated by a spontaneous mutation, natural hybridization, and polyploidy were selected by wan to suit his needs.- A detailed phylogenetic study now shows that there is a compelling association between polyploidy and domestication and that polyploidy more frequently occurs before domestication. Polyploidy and domestication are both important phenomena in plant evolution.
2. The extent of genetic variability substantially increased due to selection.- Genetic variations that alter gene activity or protein function can introduce different traits in an organism. If a trait is advantageous and helps the individual survive and reproduce, the genetic variation is more likely to be passed to the next generation.

All of the following is transcribed from DNA except Exons.
Exons are the sequence of DNA present in mature messenger RNA, some of which encode the amino acids of a protein.
these are coding sections of an RNA transcript, or the DNA encoding it, that is translated into protein.
Exons can be separated by intervening sections of DNA that do not code for proteins, known as introns.

Gap junction is present only in plant cell is incorrect, while all other statements given in options about gap junction are correct.
Gap junctions are found in animal cells also and the third type of direct junction is found within animal cells.
These junctions are channels between adjacent cells that allow for the transport of ions, nutrients, and other substances that enable cells to communicate. It is Constituted of membrane-associated proteins named connexions.

Multiline varieties are mixtures of several similar pure lines.
Multiline variety is a mixture of several pure lines of similar phenotype(height, seed colour flowering time, maturity time and various other agronomic characteristics) but has different genes for the character under consideration the disease resistance means these are isogenic lines.
Multiline varieties are mixtures of genetically related lines that have different genes for disease resistance and offer farmers a way to tame outbreaks of rust, thus stabilizing annual wheat yields.