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

In which crop, the first transgenic was developed Tobacco.
The first genetically modified crop plant was produced in 1982, an antibiotic-resistant tobacco plant. The first field trials of genetically engineered plants occurred in France and the US in 1986, tobacco plants were engineered to be resistant to herbicides.
Tobacco is the most commonly used plant for the expression of transgenes from a variety of organisms. Among the many genes from different organisms expressed in tobacco plants, genes of bacterial origin are the most common.

In nitrogen fixation plants convert atmospheric nitrogen to nitrates.
Nitrogen fixation is any natural or industrial process that causes free nitrogen (N₂), which is a relatively inert gas plentiful in air, to combine chemically with other elements to form more-reactive nitrogen compounds such as ammonia, nitrates, or nitrites.
Nitrogen-fixing plants are those whose roots are colonized by certain bacteria that extract nitrogen from the air and convert or “fix” it into a form required for their growth.

The giant chromosome is found in Salivary gland chromosome of drosophila.
The giant chromosomes are very large compared to normal chromosomes. They are also called mega chromosomes.
They increase the cell volume and DNA content so it has multiple copies of genes that allow a high level of gene expression.
Polytene giant chromosomes are found in the cells of salivary glands of Drosophila. It helps produce a large amount of adhesive mucoprotein, a type of glue before pupation.

Gene controls the production of enzymes given by E. L. Tatum.
He shared half of the Nobel Prize in Physiology or Medicine in 1958 with George Beadle for showing that genes control individual steps in metabolism.
Beadle and Tatum's key experiments involved exposing the bread mold Neurospora crassa to x-rays, causing mutations. In a series of experiments, they showed that these mutations caused changes in specific enzymes involved in metabolic pathways.

The number of bases in the single turn of the DNA helix is 10.
DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. DNA is a long polymer made from repeating units called nucleotides, each of which is usually symbolized by a single letter: either A, T, C, or G.
DNA can be twisted like a rope in a process called DNA supercoiling. With DNA in its "relaxed" state, a strand usually circles the axis of the double helix once every 10 base pairs.

Male sterility promotes Outbreeding.
The presence of male sterility leads to heterozygosity in a species as it promotes outbreeding and reduces homozygosity due to the elimination of inbreeding.
Male sterility results from the action of nuclear genes or cytoplasmic genes or both. Male sterility is caused due to pollen or anther abortion.
Outbreeding refers to matings between individuals from different populations, subspecies, or species. Outbreeding can result in a decline in reproductive fitness known as outbreeding depression, but this is less common than inbreeding depression.

The frequency of getting AABBCC individuals from a mating of two AaBbCc individuals is ¹/₆₄.
The parents with genotype AaBbCc X AaBbCc gives 64 offsprings with different genotypes, but only 1 individual will have all dominant genes i.e. AABBCC.
Genotype frequency in a population is the number of individuals with a given genotype divided by the total number of individuals in the population.

Centromere division occurs during the Anaphase stage of Mitosis.
It is the stage of mitosis after the process of metaphase when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell.
The centromeres are split, and the sister chromatids are pulled toward the poles by kinetochore microtubules. They take on a V-shape or Y-shape as they are pulled to either pole.

From the given options, Inbred × O.P var is the Top cross.
It refers to the use of highly inbred males to the females of the base population or non-inbred population.
The top cross is a cross between a superior or purebred male and inferior female stock to improve the average quality of the progeny.

a. Protein synthesis occurs in Ribosomes.
The ribosome is universally responsible for synthesizing proteins by translating the genetic code transcribed in mRNA into an amino acid sequence.
b. Golgi apparatus is Dictyosome.
In plant cells, the Golgi apparatus consists of several separate units called dictyosomes.
c. RNA synthesis occurs in Nucleosomes.
In cells, RNA elongation by RNAPII is stalled at multiple sites within a nucleosome.
d. Suicidal bags are Lysosome.
It is a membrane-bound organelle found in many animal cells. De Duve had termed the Lysosomes, the "suicide bags" or "suicide sacs" of the cells, for their hypothesized role in apoptosis.