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

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.

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.

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.

If 2n = 10, the number of chromatids in each daughter cell after meiosis-I will be 10.
Meiosis is reductional division, thus after division chromosome number in each daughter cell is halved.
Thus, the chromosome number in each daughter cell after meiosis-1 will be 5 if 2n= 10 and therefore, the number of chromatids will be 10.

French bean is the legume crop from the given option that does not fix atmospheric nitrogen through symbiotic N. fixation.
Legumes can form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. Among all legume crops beans are considered to be poor nitrogen fixers.

BTT is associated with Barley.
The BTT as a tertiary trisomic constructed in such a way that the dominant allele of a marker gene, closely linked with the translocation breakpoint of the extra chromosome is carried on the extra chromosome, and the recessive allele is carried on the two normal chromosomes that constitute the diploid complement.
The dominant marker gene may be located on the centromere segment or the trans-located segment of the extra chromosome.

First seed testing laboratory was opened under the guidance of E. Moller Holst in Denmark.
The Seed Testing Laboratory is the hub of seed quality control. Seed testing services are required from time to time to gain information regarding planting value of seed lots.
Moller Holst, established a seed testing lab in Copenhagen, Denmark 1876 -1^st Seed Testing station in US 1900- Europe 130 Seed Testing Stations 1924- International Seed Testing Association (ISTA)-to develop procedures and to promote the uniform application.

Plants that grow in salt water are known as Halophytes.
A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt sprays, such as in saline semi-deserts, mangrove swamps, marshes and sloughs and seashores.
Plants that avoid the effects of high salt even though they live in a saline environment may be referred to as facultative halophytes rather than 'true', or obligatory, halophytes.

Zeatin is a cytokinin among the given options.
Cytokinins (CK) are a class of plant hormones that promote cell division, or cytokinesis, in plant roots and shoots.
Zeatin is a cytokinin derived from adenine, which occurs in the form of a cis- and a trans-isomer and conjugates. Zeatin was discovered in immature corn kernels from the genus Zea. It promotes the growth of lateral buds and when sprayed on meristems stimulates cell division to produce bushier plants.

Osmotic pressure in a vacuolated plant cell is usually equal to TP.
Osmotic pressure is the main cause of support in many plants. When a plant cell is in a hypotonic environment, the osmotic entry of water raises the turgor pressure exerted against the cell wall until the pressure prevents more water from coming into the cell. Here, OP becomes equal to TP.
Vacuolated plant cells behave like ideal osmometers and plasmolytic contraction of the protoplast is also a concerned.