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

Genetic code was discovered by Holley, Nirenberg and Khorana.
Marshall Nirenberg, Har Gobind Khorana, and their colleagues were the first to determine the genetic code and show how the nucleic acid bases determine the sequence of the 20 different amino acids during protein synthesis.
Each gene's code uses the four nucleotide bases of DNA: adenine (A), cytosine (C), guanine (G) and thymine (T) in various ways to spell out three-letter “codons” that specify which amino acid is needed at each position within a protein.

The progeny of the breeder seed is referred to as the Foundation seed.
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 certified seed shall be the progeny of foundation seed and its products shall be so handled as to maintain specific genetic identity and purity according to the standards prescribed for the crop being certified.

The molecular basis of organ differentiation depends on the modulation in transcription by the Transcription factor.
A transcription factor is a molecule that controls the activity of a gene by determining whether the gene's DNA (deoxyribonucleic acid) is transcribed into RNA (ribonucleic acid).
Proteins are involved in the process of converting, or transcribing, DNA into RNA. Transcription factors include a wide number of proteins, excluding RNA polymerase that initiate and regulate the transcription of genes.

The phenomenon of linkage was first observed by Bateson and Punnet in sweet pea in 1906.
Linkage is the tendency for genes or segments of DNA closely positioned along a chromosome to segregate together at meiosis, and therefore be inherited together.
The linkage between two or more loci controlling different desirable characteristics is advantageous for a plant breeder. A linkage between genes controlling two different desirable characters will help in the simultaneous improvement of both characters.

Examples of transposons in the human genome are Both LINE and SINE.
Transposable elements (TEs) are mobile repetitive sequences that make up large fractions of mammalian genomes, including at least 45% of the human genome.
SINEs and LINEs are short and long interspersed retro transposable elements, respectively, that invade new genomic sites using RNA intermediates.
SINEs and LINEs are found in almost all eukaryotes and together account for at least 34% of the human genome.

The cell cycle is regulated by all of the above which are Cyclins, Cyclin-dependent kinase and Inhibitory proteins.
The cell cycle is regulated by many cyclins, cyclin-dependent kinases (CDKs) as well as Inhibitory proteins which are a group of serine/threonine kinases. They form complexes with cyclins to stabilize, activate, and phosphorylate CDKs in specific phases.
These are serine/threonine protein kinases that phosphorylate key substrates to promote DNA synthesis and mitotic progression.

Exosmosis takes place when a plant cell is put in a Hypertonic solution.
Exosmosis is the movement of solvent out of the cell. Due to exosmosis, the cell shrinks.
Exosmosis occurs in the presence of hypertonic solutions. This happens because the solute concentration of the surrounding solution is higher than that inside the cytoplasm.

The correct option is a-2, b-1, c-4, d-3.
a) Artificial hybridization of radish (Raphanus sativus) and cabbage (Brassica oleracea) (both 2N = 18) produces a sterile first-generation hybrid with one diploid chromosome set from either parent. Tetraploidization eventually produces a stable, true-breeding hybrid Raphanobrassica.
b) Nicotiana digluta was produced by pollinating a triploid Nicotiana Tabacum plant (2n = 72) with N. glutinosa. N. glutinosa × N. Tabacum = N. digluta.
c) Triticale is a hybrid of wheat (Triticum aestivum) and rye (Secale cerele) first bred in laboratories during the late 19^th century in Scotland and Germany. When crossing wheat and rye, wheat is used as the female parent and rye as the male parent (pollen donor).
d) Gossypium hirsutum, also known as upland cotton or Mexican cotton. It is a cross-bred cultivar (Gossypium harbaceum × Gossypium Raimondii) with varying fibre lengths and tolerances to several growing conditions.

The concept of a multiline cultivar was developed by Jensen (1952).
The concept of the multiline as an approach to the long-term control of diseases in self-pollinated crops was first presented by Jensen, 1952 in oats and next by Borlaug and Gibler (1953) in wheat.
The multiline approach is concerned with the management of resistance genes that condition vertical resistance. Multiline crop cultivars are phenotypically similar (height, grain type) but genetically different against insect pests and diseases.

Of the total water uptake by a plant, passive absorption of water accounts for 98%.
Passive absorption occurs due to osmosis usually when the rate of transpiration is typically higher than normal. In this way, water is transported from the roots to the leaves of the plants through the xylem tissue.
It occurs more rapidly because of the transpiration pull and by the action of cohesive and adhesive force in water molecules that enables the continuous flow of water.