Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Loading of phloem means pouring sugar into phloem.
Phloem is the living tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and is known as photosynthates, in particular the sugar sucrose, to the rest of the plant. This transport process is called translocation.
The phloem is composed of still-living cells that transport sap. The sap is a water-based solution, but rich in sugars made by photosynthesis. These sugars are transported to non-photosynthetic parts of the plant, such as the roots, or into storage structures, such as tubers or bulbs.

During the dark reaction, the three carbon atoms of 3-PGA are derived from RuBP + CO₂.
Dark reactions of photosynthesis are a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose. This is because the process requires NADPH, which is short-lived and comes from light-dependent reactions.
The CO₂ that is captured by enediol produces an unstable six-carbon compound called 2-carboxy 3-keto 1,5-biphosphoribotol that immediately splits into 2 molecules of 3-phosphoglycerate , a 3-carbon compound. Two 3-PGAs are produced for every CO₂ that enters the cycle, so this step utilizes two ATP per CO₂ fixed.

The term "Virus" means Poison.
The word Virus is from the Latin neuter virus referring to poison and other noxious liquids, from the same Indo-European base as Sanskrit viṣa, Avestan visa, and ancient Greek all meaning 'poison'.
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.

The green ear or downey mildew of pearl millet was first time reported in India by E. J. Butler in 1907.
Sir Edwin John Butler was an Irish mycologist and plant pathologist. He became the Imperial Mycologist in India. He has been called the Father of Mycology and Plant Pathology in India.
The downy mildew disease in pearl millet was first reported in India as the disease of ill-drained lands where it developed into severe epidemics. In this disease, the leaf streaks turn brown and the leaves become shredded longitudinally.

Bacterial photosynthesis differs from that of higher plants in not liberating oxygen.
In plants, the proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane.
Apart from this, the main difference between bacterial and plant photosynthesis is plant liberates oxygen whereas bacterias do not generate oxygen.

Development of shoot and root in tissue culture is determined by cytokinin and auxin ratio.
The pioneering work has shown that a high auxin/cytokinin ratio induces root regeneration, whereas a low ratio promotes shoot induction.
High cytokinin-to-auxin ratios correlated with the shooty phenotype of transformed tissues propagated in vitro in the absence of added growth hormones.

Kamal bunt of wheat gives a foul smell in the field due to the presence of the volatile compound Trimethyl amine.
Karnal bunt (also known as partial bunt) is a fungal disease of wheat, durum wheat, and triticale. The smut fungus Tilletia indica, a basidiomycete, invades the kernels and obtains nutrients from the endosperm, leaving behind waste products with a disagreeable odour.
The black powder which gives a foul smell due to the presence of Trimethyl amine is a mass of thick-walled dark brown spores of the fungus known as teliospores.

Tiechoic acid is present in Gram +ve bacteria.
The peptidoglycan layers of many gram-positive bacteria are densely functionalized with anionic glycopolymers called wall teichoic acids (WTAs).
These polymers play crucial roles in cell shape determination, regulation of cell division, and other fundamental aspects of gram-positive bacterial physiology.

'Buckeye rot' is a disease of Water chestnut.
Buckeye rot is one of several fruit-rotting diseases that attack both green and ripe fruit, especially where the fruit touches the soil. The lesion is rounded with alternating bands of light and dark brown in concentric circles. The lesion appears water-soaked at first but later may become leathery on the surface.
Staking or plastic mulch to prevent fruit from contacting the soil is an effective control. The disease is worse in hot, wet weather. Fungicides offer little control to soil-contact type diseases.

Rock phosphate has a chemical composition Ca₃(PO₄)₂.
It is a calcium salt of phosphoric acid with the chemical formula Ca₃(PO₄)₂. It is also known as tribasic calcium phosphate (TCP) and bone phosphate of lime (BPL).
The molar mass of the compound is 310.18, and appears as a white amorphous powder with low solubility.
It exists as three crystalline polymorphs α, α′, and β. The α and α′ states are stable at high temperatures.