Genetics And Plant Breeding - Study Mode
[#326] Random assortment of genes will occur if the genes are located on
Correct Answer
(B) Different chromosomes
Explanation
Solution: A random assortment of genes will occur if the genes are located on different chromosomes. Random assortment contributes to the mixing up of genetic material in the gametes. This means that, although siblings often resemble each other, they are never identical unless they are monozygotic twins. Independent assortment occurs spontaneously when alleles of at least two genes are assorted independently into gametes.
[#327] Replacement of purine with another purine base is known as
Correct Answer
(D) Transition
Explanation
Solution: The replacement of purine with another purine base is known as Transition. Transition is the substitution of a purine from another purine base or pyrimidine from another pyrimidine (C⟷T or A⟷G). A transition is a DNA point mutation that substitutes one purine for another or one pyrimidine for another, all other point mutations are called transversion.
[#328] Tag colour of Foundation seed is
Correct Answer
(C) White
Explanation
Solution: The tag colour of the Foundation seed is white. The progeny of breeder seed is produced by recognized seed-producing agencies in the public and private sector, under the supervision of seed certification agencies in such a way that its quality is maintained according to prescribed field and seed standards. A white colour certificate is issued for foundation seeds by seed certification agencies.
[#329] A mutant gene in Hordeum vulgare produces albino seedlings at temperature below 8°C. But when the seedling carrying this gene are grown at 19°C or above, they develop into normal green seedlings. The characters whose development depends upon a specific environment are known as
Correct Answer
(C) Threshold characters
Explanation
Solution: Discrete characters are traits that have distinct, separate categories (like flower color being red or white). They don't change based on the environment in the way described in the question. Quantitative characters are traits that can be measured on a continuous scale (like height or weight). They are usually influenced by many genes and the environment, but this question describes a very specific temperature trigger. Threshold characters are traits that only express themselves when a certain environmental condition is met or exceeded. In this case, the green color develops only when the temperature is above a certain threshold (8°C). Below that, the albino (white) trait appears. This perfectly matches the description in the question! Pleiotropy is when a single gene affects multiple different traits. The question only describes one visible trait (color), so pleiotropy doesn't fit. Therefore, since the albino seedling only turns green above a specific temperature, the character's development is dependent on crossing a temperature threshold .
[#330] Pusa Sugandha-5 is new variety of
Correct Answer
(A) Rice
Explanation
Solution: Pusa Sugandha-5 is a new variety of Rice. A semi-dwarf high-yielding aromatic rice variety suitable for multiple cropping systems in northern India. It is a highly profitable paddy variety, with a crop duration of 140 to 145 days.