Genetics And Plant Breeding - Study Mode

[#761] 3D view of t RNA is
Correct Answer

(C) L shaped

Explanation

Solution: 3D view of tRNA is L-shaped. tRNA adopts an "L" shape , with the acceptor end (⚞⚟) on one end and the anticodon (⚞⚟) on the other end. At the acceptor end, amino acids are attached via the 2'-OH or 3'-OH group of the last nucleotide in the acceptor stem.

[#762] Vertical resistance can be exploited through
Correct Answer

(D) All of the above

Explanation

Solution: Vertical resistance refers to resistance that is usually governed by one or a few major genes and is often race-specific. Option A: Development of varieties with individual major gene is a method to exploit vertical resistance because it involves using specific genes that provide resistance to certain races of a pathogen. Option B: Gene pyramiding and gene developing enhances durability by combining multiple resistance genes, thereby increasing the effectiveness of vertical resistance. Option C: Development of multiline involves creating a mixture of lines, each with different major resistance genes, which can reduce the likelihood of pathogen adaptation. Hence, all these approaches can be used to exploit vertical resistance effectively.

[#763] Coupling and repulsion hypothesis was given by
Correct Answer

(C) Bateson

Explanation

Solution: The coupling and repulsion hypothesis was given by Bateson. Bateson and Punnett in 1906, described a cross in sweat pea, where failure of gene pairs to assort independently was exhibited. Bateson explained the lack of independent assortment through a hypothesis known as the coupling and repulsion hypothesis. Later on, coupling and repulsion were discovered to be two different aspects of linkage.

[#764] The accessory chromosome explanation was proposed by
Correct Answer

(B) Mc clung

Explanation

Solution: The accessory chromosome explanation was proposed by Mc clung. Clarence Erwin McClung was an eminent American zoologist and prairie pioneer cytologist who discovered the role of chromosomes in sex-determination. In 1901 McClung hypothesized that sex determination in grasshoppers is dependent upon the number of X chromosomes within a cell. Maleness in grasshoppers is determined by the absence of a second X chromosome (XO), while femaleness is induced by the presence of two X chromosomes (XX). This theory helped to prove that chromosomes carry genetic information that determines phenotype.

[#765] The point mutation occurs due to
Correct Answer

(C) Alterations of sequences of bases in DNA

Explanation

Solution: The point mutation occurs due to Alterations of sequences of bases in DNA. Point mutation, is a change within a gene in which one base pair in the DNA sequence is altered. Point mutations are frequently the result of mistakes made during DNA replication, although modification of DNA, such as through exposure to X-rays or ultraviolet radiation, also can induce point mutations.