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

The enzyme whose activity level is determined by tetrazolium test is Dehydrogenase.
Tetrazolium test, commonly known as the TZ test for seed viability has, therefore, been developed to furnish quick estimates of seed's germinability.
The test indirectly measures the respiration processes that occur in the mitochondria of the cells that make up the tissues of the seeds. The reducing reaction of the solution of the tetrazolium salt under the action of dehydrogenase enzymes results in triphenylformazan, which presents a red carmine colouration. The test is very useful in processing, handling, storing and marketing.

The correct answer is Option A: R-line.
Let's break down why:
In the context of hybrid seed production, especially in crops like rice and maize, we use different lines with specific roles.
A-line (Male-sterile line): This line is unable to produce functional pollen. It's used as the female parent in hybrid seed production.
B-line (Maintainer line): This line is used to maintain the A-line. It's genetically similar to the A-line but possesses normal pollen fertility.
R-line (Restorer line): This line carries a fertility restorer gene (Rf gene). When it pollinates the A-line (which is male-sterile), the resulting hybrid offspring regain fertility. So, the hybrid plant can produce viable seeds.
C-line: While C-lines might be used in some specific breeding programs, it's not a standard term associated with the restorer system. It generally doesn't directly represent the restorer line in hybrid seed production.
Therefore, the restorer line is specifically represented as the R-line because it's responsible for restoring fertility in the hybrid progeny.

a. Walter Sutton and Theodor Boveri are credited with developing the Chromosomal Theory of Inheritance, which states that chromosomes carry the unit of heredity.
b. Nilsson Ehle proposed a multifactor hypothesis that is to explain quantitative variation by assuming the interaction of a large number of genes (polygenes) each with a small additive effect on the character.
c. The one gene-one enzyme hypothesis concept was proposed by George Beadle and Edward Tatum in an influential 1941 paper. It means that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway.
d. Wilhelm Johannsen proposed his pure line theory and the genotype/phenotype distinction, a work that is prized as one of the most important founding contributions to genetics and Mendelian plant breeding.

Hand emasculation and dusting are done in Tomato, Cotton and Gingelly.
Emasculation is the process of removal of stamens or anthers or the killing of pollen grains of a flower without affecting the female reproductive organs. Simply it means the removal of masculinity.
Hand emasculation is done in the species with large flowers, forceps are used to remove the anthers. The process is done one day before the anthers are expected to dehisce or mature and the stigma is likely to become mature. The fair time is 4 - 6 p.m. in the evening.
Flowers are pollinated by dusting them with fresh pollen obtained from the desired male plant or by shaking a spike which is shedding pollen over the exposed stigmas.

In cross pollinated species, a true breeding line obtained by continuous inbreeding is called Inbreed.
A true breeding (pure breeding strain) means it has undergone continuous self pollination having stable train inheritance from parent to offspring.
Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically.

The endosperm of an organism has chromosome 30. So the chromosome in the root cell is 20.
The endosperm is triploid, i.e. 3n.
3n = 30
Therefore n = $$\frac{{30}}{3} = 10.$$
Each cell of the root is diploid that will be 2n, that will be 2 × 10= 20

The unit of inheritance is a gene.
A gene is the basic physical and functional unit of heredity.
The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA.
Genes are made up of DNA. Some genes act as instructions to make molecules called proteins.

Allosomes are Sex chromosomes.
Allosome is a chromosome that differs from an ordinary autosome in form, size, and behavior. The human sex chromosomes, a typical pair of mammal allosomes, determine the sex of an individual created in sexual reproduction.
Nettie Stevens and Edmund Beecher Wilson both independently discovered sex chromosomes in 1905.

A membrane that allows selective movement of molecules through it is own a Semipermeable membrane.
It is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by osmosis.
The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute.
Biological membranes are selectively permeable, with the passage of molecules controlled by facilitated diffusion, passive transport or active transport regulated by proteins embedded in the membrane.

Centrioles generally have 9 microfibrils.
The centriole is a cylindrical organelle composed mainly of a protein called tubulin.
It is made up of nine sets of short microtubule triplets, arranged in a cylinder.
Centrioles are involved in the organization of the mitotic spindle and the completion of cytokinesis.