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

The structure of chromosomes can be observed best during Metaphase.
Metaphase is a stage of mitosis in the eukaryotic cell cycle in which chromosomes are at their second-most condensed and coiled stage. These chromosomes, carrying genetic information, align in the equator of the cell before being separated into each of the two daughter cells.
During metaphase, the nucleus dissolves and the cell's chromosomes condense and move together, aligning in the center of the dividing cell.

Cryopreservation is not suitable for preserving Aerobic organisms.
It is a process where organisms, organelles, cells, tissues, extracellular matrix, organs, or any other biological constructs susceptible to damage caused by unregulated chemical kinetics are preserved by cooling to very low temperatures using liquid nitrogen.
Cryopreservation methods seek to reach low temperatures without causing additional damage caused by the formation of ice crystals during freezing.

The seed replacement ratio of Pearl millet is 1 : 200.
It is a measure of how much of the total cropped area was sown with certified seeds in comparison to farm-saved seeds.
In other words, it is the percentage of area sown out of the total area of the crop planted in the season by using certified/quality seeds other than the farm-saved seed. In simple terms, it is a measure of the cropped area covered with quality seed.

Resistance exhibited by young seedlings is called Seedling resistance.
Seedling resistance is resistance that begins in the seedling stage of plant development and continues throughout its lifetime.
It is typically expressed at all growth stages, conferred by a single 'major effect' gene often associated with a hypersensitive response, and is often race-specific.

The ecological suicide that occurred in cotton is due to Ethylene.

Male sterility was reported by Koelreuter.
Joseph Gottlieb Kolreuter was the first to document male sterility in plants. In the 18th century, he reported on anther abortion within species and specific hybrids.
This could be because the male sporophyte and gametophyte are less protected from the environment than the ovule and embryo sac. Male-sterile plants can set seeds and propagate.

Guard cells in monocot leaves are Dumb-bell shaped.
Monocots contain dumbbell-shaped guard cells, surrounding their stomata. Monocots contain stomata in both upper and the lower epidermis of leaves.
Guard cells optimize leaf gas exchange in response to changing environmental conditions and their turgor is controlled by alterations in atmospheric CO₂ concentration, light intensity, humidity and the drought hormone abscisic acid.

Global Gene Bank of rice is located in Los Baños, Philippines.
It is an independent, nonprofit, research and educational institute, founded in 1960 by the Ford and Rockefeller foundations with support from the Philippine government.
The International Rice Research Institute is the world’s premier research organization dedicated to reducing poverty and hunger through rice science; improving the health and welfare of rice farmers and consumers; and protecting the rice-growing environment for future generations.

In wheat and rice, the genetic purity of a variety can deteriorate due to Mechanical contamination with seeds of other varieties.
The genetic purity during multiplication stages is prone to contamination due to the presence of pollen shedders as well as physical admixtures during processing.
The deterioration sets in due to natural crossing with undesirable types, diseased plants or off types.

Disease and insect resistance are governed by Plasma genes, Oligogenes and Polygenes.
The plasma gene is an extranuclear determiner of hereditary characteristics with a capacity for replication similar to that of a nuclear gene.
Oligogene is a gene that produces or significantly affects the expression of a qualitative heritable characteristic, acting either alone or with a few other genes.
A polygene refers to a group of genes that when expressed together produce a particular phenotype or trait.