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

The bulk breeding method was developed by Nilson Ehle (1908).
It is a method that can handle segregating generations, in which F₂ and subsequent generations are harvested in bulk to grow the next generation. At the end of bulking period, individual plant selection and evaluation are carried out similarly to the pedigree method.
It refers to a species that is grown in bulk plots with or without selection, a part of the bulk seed is used to grow the next generation and individual plant selection is practiced in F₆ or later generation. It was first used by Nilsson Ehle in 1908.

When F₁-plants heterozygous for tallness is selfed, F₂-generation has both tall and dwarf plants. This proves the principle of the Law of independent assortment.
The Principle of Independent Assortment describes how different genes independently separate from one another when reproductive cells develop. An Independent assortment of genes and their corresponding traits was first observed by Gregor Mendel in 1865 during his studies of genetics in pea plants.

a. Bacteriophages, also known as phages, are viruses that infect and replicate only in bacterial cells. They are ubiquitous in the environment and are recognized as the most abundant biological agent on earth.
b. A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of proteins called protomers.
c. Oncogenes when activated cause Cancer. An oncogene is a mutated gene that has the potential to cause cancer. Before an oncogene becomes mutated, it is called a proto-oncogene, and it plays a role in regulating normal cell division.
d. Human immune deficiency causes AIDS. Acquired immunodeficiency syndrome (AIDS) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body's ability to fight infection and disease.

Arize-AZ 8433 DT, a mid-duration rice variety launched by Bayer, offers protection from BLB and BPH.
In the event of a BPH and BLB attack, Arize AZ 8433 DT from Bayer offers a yield advantage of up to 20 to 30 percent over other susceptible open-pollinated varieties (OPVs), where yield losses could be up to 100 percent.

a. Lipid biosynthesis occurs in peroxisome is wrong.
The endoplasmic reticulum (ER) is the main site for lipid synthesis. Intracellular lipid trafficking is necessary to maintain most other organelle membranes as they cannot synthesize lipids de novo.
b. Removal of toxic chemicals done by SER is true.
SER is a membrane-bound network of tubules without surface ribosomes. SER is not involved in protein synthesis. Its main function is the synthesis of lipids, steroids, and carbohydrates, as well as the metabolism and removal of exogenous substances, such as drugs or toxins.
c. Lysosome is suicidal bag is correct.
Lysosomes are capable of digesting nucleic acid, polysaccharides, fats and proteins. Along with them lysosomes also digest or damage their cells with their enzymes, which leads to cell death.
d. Protein synthesis taking place by ribosomes is also correct.
The ribosome is universally responsible for synthesizing proteins by translating the genetic code transcribed in mRNA into an amino acid sequence.

Systematic hybridization on a scientific basis began with the work Koelreuter-Nicotiana.
Kolreuter began with the systematic study of plant hybridization.
This author performed crosses between Nicotiana paniculata and N. rustica (Kolreuter in 1761). As a result of these crosses, he made important conclusions about plant hybridization.

If a heterozygous Black fur mouse (Bb) mates with a homozygous Brown mouse (bb), the percentage of their offspring who will have Black flour is 50%.
Black fur mouse (Bb) X Brown mouse (bb), the offsprings will be Bb, Bb, bb, bb. Half of the offspring produced will have black fur.

Crossing over between homologous chromosomes never exceeds 50%.
The recombination frequency between two genes cannot be greater than 50% because a random assortment of genes generates 50% recombination.
Non-linked genes produce 1 : 1 parental to non-parental. Thus, the recombination frequency would be non-parental/total, i.e. $$\frac{1}{{1 + 1}} = 50\% .$$

Multiple effects of a single gene are known as Pleiotropy.
It describes the genetic effect of a single gene on multiple 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.
Pleiotropy means that a single gene affects two or more characters. It is a single gene that affects the fitness of the organism at two or more ages. It is convenient to categorize the combinations of age-specific pleiotropic effects.

Autopollyplidy can be found in Sugarcane, Cotton and Mustard.
Autopolyploidy appears when an individual has more than two sets of chromosomes, both of which are from the same parental species.
Autopolyploids can be obtained after treatment with chemicals such as colchicine or oryzalin, which affects spindle formation and induces chromosome nondisjunction during mitosis. The formation of unreduced gametes may also be a source of autopolyploid plants, like sugarcane, Cotton and Mustard.