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

The total of all the seed attributes that can withstand emergence under favourable conditions is called vigour.
Seed vigour is the energy or stamina of the seed in producing elite seedlings. It is the total of all seed attributes that enables its regeneration under any given conditions.
Seed vigour determines the level of performance of seed or seed lot during germination and seedling emergence.

The mineral constituent of the cell wall is calcium.
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It is composed of the polysaccharides cellulose, hemicelluloses and pectin.
The cells are held together and share the gelatinous membrane called the middle lamella, which contains magnesium and calcium pectates.

A pair of genes are linked if their recombination frequency in the test cross is Less than 50%.
If the genes are far apart on a chromosome or different chromosomes, the recombination frequency is 50%.
In this case, the inheritance of alleles at the two loci is independent. If the recombination frequency is less than 50% we say the two loci are linked.

Light energy is converted into chemical energy is a remarkable feature of photosynthesis.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities.
Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water hence the name photosynthesis, from the Greek word phōs, "light", and synthesis, "putting together".

The analogue of 5-bromouracil is Thymine.
5-Bromouracil (BrU) is a base analogue of thymine (T) which can be incorporated into DNA.
5 bromouracil pairs with thymine because the analog of thymine has a higher tendency to form an enol tautomer with its resembling base that is thymine.

In mitosis, the longest phase is the prophase.
The first and longest phase of mitosis is prophase. During prophase, chromatin condenses into chromosomes, and the nuclear envelope breaks down.
In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles of the cell.

In India, for hybrid seed production in maize, we use Cytoplasmic genetic male sterility.
The cytoplasmic-genetic male sterility is used commercially to produce hybrid seed in maize, bajra and jowar.
A triple cross may be produced by crossing a single cross with fertility restoring inbred so that all the plants in the triple cross would be male fertile.

In the mechanism of opening and closing of stomata, the important factor is the shape of the guard cells.
When the concentration of potassium ions increases in the guard cell, it allows the guard cell to absorb water from the surrounding cells. This turgidity of the guard cell cause opening of the stomata. However, decrease in the concentration of potassium ions, makes guard cell flaccid and ultimately makes it close.

a. Shull discovered Heterosis. George Harrison Shull was an eminent American plant geneticist. He also described heterosis in maize in 1908 and made several other key discoveries in the emerging field of genetics.
b. Waldeyer discovered Chromosome. He coined 1888 the term "chromosome" to describe them. Among his many other anatomical and embryological studies.
c. Fairchild discovered the first hybrid. In 1716 - 17 he was the first person to scientifically produce an artificial hybrid, Dianthus Caryophyllus barbatus, known as "Fairchild's Mule", a cross between a Sweet William (Dianthus barbatus) and a Carnation pink.
d. Watson and crick discovered a model of DNA. The discovery in 1953 of the double helix, the twisted-ladder structure of deoxyribonucleic acid, by James Watson and Francis Crick marked a milestone in the history of science.