Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

In photosynthesis, oxygen is liberated during Hydrolysis of water.
Two water molecules are oxidized by the energy of four successive charge-separation reactions of photosystem II to yield a molecule of diatomic oxygen and four hydrogen ions.
The electrons yielded are transferred to a redox-active tyrosine residue that is oxidized by the energy of P680⁺. In light, the electron acceptor is reduced and oxygen is evolved.

Loose smut is internally seed borne.
Loose smut of barley is caused by Ustilago nuda. It is a disease that can destroy a large proportion of a barley crop. Loose smut replaces grain heads with smut, or masses of spores that infect the open flowers of healthy plants and grow into the seed.
The major symptom of loose smut is the "smutted" grain heads, which contain masses of black or brown spores.
The most widely used method of control for loose smut is using treated seed. Seeds are typically treated with a systemic fungicide to kill any fungus that may be inside.

The composition of Bordeaux mixture is 5lb Copper sulphate + 5lb lime + 50 gallon water.
Bordeaux mixture is a mixture of copper (II) sulphate (CuSO₄) and quicklime (CaO) used as a fungicide. It was invented in the Bordeaux region of France in the late 19^th century, hence named after that.
Bordeaux mixture achieves its effect using the copper ions (Cu²⁺) of the mixture. These ions affect enzymes in the fungal spores in such a way as to prevent germination.
It is sprayed on plants as a preventive treatment; its mode of action is ineffective after a fungus has become established.

Fosetyl Al fungicide has both basipetal and acropetal movement.
Fosetyl-aluminium is a pesticide used as a fungicide to control various diseases on food and feed crops. This compound is rapidly converted to phosphonic acid, which is regularly detected in poorly processed food products.
Fosetyl- al is an active ingredient, and was developed in France at the end of the 1970s, is characterized by acropetal and basipetal translocation in plants.

On an average 1 kg N, P₂O₅ and K₂O are added to increase grain yield by 10 kg.
Nitrogen, phosphorus, and potassium are macronutrient uptake by crop yields and crop residues by attaining high-input potential yields compared to that low-input yields, and the number of fertilizers applied.
On average 1 kg of N, P₂O₅ and K₂O are added to increase grain yield by 10 kg.

In alcoholic fermentation, Triose phosphate is electron donor while acetaldehyde is electron acceptor.
Alcoholic fermentation is a complex biochemical process during which yeasts convert sugars to ethanol, carbon dioxide, and other metabolic by-products that contribute to the chemical composition and sensorial properties of the fermented foodstuffs.
The energy released by these exothermic reactions is used to phosphorylate two ADP molecules, yielding two ATP molecules, and reduce two molecules of NAD⁺ to NADH. The 2 pyruvate molecules are broken down, yielding two molecules of acetaldehyde and giving off two molecules of carbon dioxide.

The incidence of black scurf of potato is more in Sandy soil.
Black scurf is caused by the fungus Rhizoctonia solani, which can exist in the soil in the absence of potatoes.
Rhizoctonia solani is a soil pathogen and thus is affected by soil conditions. Black scurf and stem canker are more severe in soils that are cool and moist. It is more common in crops grown in sandy to sandy loam and moderately wet soils.

Some flowers possess pleasant odour and attractive colours for Entomophily.
Entomophily or insect pollination is a form of pollination whereby pollen of plants is distributed by insects.
Flowers pollinated by insects typically advertise themselves with bright colours, sometimes with conspicuous patterns leading to rewards of pollen and nectar; they also have an attractive scent which in some cases mimics insect pheromones.

The phenomenon of embryo formation from a vegetative cell derived from zygote is known as Adventive polyembryony.
Polyembryony is the phenomenon of two or more embryos developing from a single fertilized egg.
Adventitious embryonic from nucellar cells is the mechanism leading to apomixis in most plants or it can be referred to as formation of extra embryos by the impact of sporophytic budding from as adventitious cells.

The rate of transpiration is measured by Ganong's potometer.
A potometer, is a device used for measuring the rate of water uptake of a leafy shoot which is almost equal to the water lost through transpiration.
Francis DarwinCharles Darwin Ganong Bose designed and invented Ganong’s potometer. The Ganong's potometer is composed of a glass tube, which is bent twice, and a glass cylinder with a wide mouth also a capillary tube is inserted into a horizontal glass bar attached to a reservoir.