Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

In C₄ plants, chloroplasts are also found in Bundle sheath cells.
C₄ plants have two types of photosynthetic cells, mesophyll and bundle sheath cells. Mesophyll chloroplasts are randomly distributed along cell walls, whereas bundle sheath chloroplasts are located close to the vascular tissues or mesophyll cells depending on the plant species.

Chief pollinators of crops are Bees.
A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.
Insects are the major pollinators of most plants, and insect pollinators include all families of bees and most families of aculeate wasps; ants; many families of flies; many lepidopterans (both butterflies and moths); and many families of beetles.
Bees typically are fuzzy and carry an electrostatic charge. Both features help pollen grains adhere to their bodies, but they also have specialized pollen-carrying structures; in most bees, this takes the form of a structure known as the scopa, which is on the hind legs of most bees, and/or the lower abdomen, made up of thick, plumose setae.

The incorporation of two or more major genes in a variety for specific resistance to pathogens is known as Gene pyramiding.
Gene pyramiding refers to the process of stacking multiple genes into a single genotype to combine desirable traits through recombinant DNA technology or conventional breeding. This approach has resulted in the so-called 'second generation' of GE plants.

Carbon disulphide is the 1^st soil fumigant.
Carbon disulfide is a liquid-type fumigant sold in metal cans or drums. It penetrates well and does not reduce seed germination.
Carbon disulfide is used in many industries. It's used to make rubber, viscose rayon, cellophane and carbon tetrachloride.

Photosynthetic enhancement with flashing light was first observed by Emerson and Arnold.
Emerson and William Arnold found that "the yield per flash reached a maximum when just 1 out of 2500 chlorophylls absorbed a quantum".
Next, in 1939, Emerson demonstrated that between 8 and 12 quanta of light were needed to produce one molecule of oxygen. Thus, changes in flashing light lead to enhancement in the photosynthesis process.

Violet and blue are primarily absorbed b carotenoids.
Carotenoids are essential compounds along with chlorophylls in photosynthetic bacteria, algae, and plants and are involved in photosynthesis and photoprotection.
Carotenoids harvest light energy and transfer this energy to chlorophylls through singlet-singlet excitation transfer.
Carotenoids also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi.

The micronutrient needed in the smallest amount is Molybdenum.
Mo is the least abundant essential micronutrient found in most plant tissues and is often set as the base from which all other nutrients are compared and measured. Molybdenum is utilized by selected enzymes to carry out redox reactions.
Molybdenum is required at very low levels where it is known to participate in various redox reactions in plants as part of the pterin complex Moco.

Meiosis is best seen in Gamete.
Meiosis means, 'lessening' since it is a reductional division is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells.
The organism's diploid germ-line stem cells undergo meiosis to create haploid gametes, which fertilize to form the zygote.
As a result, the production of gametes with half the number of chromosomes as the parent cell is the same.

The attack of sheath blight of rice (caused by Rhizoctonia solani) is more during the Active tillering stage.
Rice sheath blight disease, caused by the basidiomycetous necrotroph Rhizoctonia solani, became one of the major threats to rice cultivation worldwide, especially after the adoption of high‐yielding varieties.
In rice, R. solani can infect the plant at any growth stage (Dath, 1990). The incidence of sheath blight is more severe in early maturing, semi-dwarf, highly tillering, and compact cultivars. The disease severity and incidence increase with plant age.

Oxygen-containing carotenoids are Xanthophylls.
Xanthophylls are yellow pigments that occur widely in nature and form one of two major divisions of the carotenoid group; the other division is formed by the carotenes.
Xanthophylls are a class of oxygen-containing carotenoid pigments, their content of oxygen causes xanthophylls to be more polar than carotenes, and causes their separation from carotenes in many types of chromatography.