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

The four stages of development of genetics up to the 20^th century are Lamarckism, Weismannism, Darwinism and Mendelism.
Lamarckism, also known as Lamarckian inheritance or neo-Lamarckism, is the notion that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime. It is also called the inheritance of acquired characteristics or more recently soft inheritance.
Weismannism's main contribution at one time also known as Weismannism, according to inheritance (in a multicellular animal) only takes place using the germ cells and the gametes such as egg cells and sperm cells.
Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809 - 1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce.
Mendelism is a term that refers to the single-gene trait's theoretical principles of heredity, which are taken from Gregor Mendel's principles, also known as Mendel's laws. Gregor Mendel conducted several experiments on pea plants for seven years and then postulated the laws of inheritance.

Multiplines are the mixture of Isogenic lines.
Multiline variety is a mixture of several pure lines of similar phenotype (height, seed colour flowering time, maturity time and various other agronomic characteristics) but has different genes for the character under consideration the disease resistance means these are isogenic lines.
Isogenic lines are defined as individuals that possess the same genotype irrespective of their homo- or heterozygous nature.

The synthetic variety of maize was produced by combining 10 lines the loss in vigour in F₂ generation is ¹/₁₀.

Brassica juncea is an amphidiploid between B. nigra and B. compestris.
Brassica juncea L. belongs to the mustard family and has numerous common names used, e.g., brown mustard, Chinese mustard, or oriental mustard.
Brassica juncea is an amphidiploid with 18 chromosomes having in its genetic system the A genome (Brassica campestris) and the 8-chromosome B genome (Brassica nigra). Considerable natural variability exists under the A genome.

The process due to which allopolyploids behave like diploids only in bivalent formation is Diploidization.
Diploidization is the process of converting a polyploid genome back into a diploid one.
It involves many changes in genome organization that ultimately restore bivalent chromosome pairing and disomic inheritance, and resolve dosage and other issues caused by genome duplication.

Tiger project is a holistic approach to the conservation of Tigers.
Project Tiger is a tiger conservation programme launched in April 1973 by the Government of India during Prime Minister Indira Gandhi's tenure.
The project aims at ensuring a viable population of the Bengal tiger in its natural habitats, protecting it from extinction, and preserving areas of biological importance as a natural heritage that represent the diversity of ecosystems across the tiger's range in the country.
It ensures a viable tiger population for economic, scientific, cultural, aesthetic and ecological values.

The branch of science that deals with study of pollen are known as Palynology.
Palynology is the study of plant pollen, spores and certain microscopic plankton organisms.
The term is commonly used to refer to a subset of the discipline, which is defined as "the study of microscopic objects of macromolecular organic, not capable of dissolution in hydrochloric or hydrofluoric acids".

One gene influencing several traits is known as Pleiotropy.
“PLEIOTROPY” refers to the phenomenon in which a single locus affects two or more unrelated phenotypic traits and is often identified as a single mutation that affects two or more wild-type traits.
It occurs when one gene influences two or more seemingly unrelated phenotypic traits. The underlying mechanism is genes that code for a product that is either used by various cells or has a cascade-like signaling function that affects various targets.

The basis of evolution is variation.
Variation is a change or difference in the amount or level of something. The differences in characteristics between individuals of the same species.
Natural selection can only take place if there is variation, or differences, among individuals in a population. Importantly, these differences must have some genetic basis; otherwise, selection will not lead to change in the next generation.

The phenotypic ratio of monohybrid cross in F₂ generation is 3 : 1.
In the offspring of monohybrid crosses, or F₂ generation, Mendel repeatedly observed a phenotype ratio of three plants with the dominant phenotype to one plant with the recessive phenotype (3 : 1) in the F₂ generation.