Plant Pathology - Study Mode
[#941] Development of shoot and root in tissue culture is determined by
Correct Answer
(A) Cytokinin and auxin ratio
Explanation
Solution: 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.
[#942] Kamal bunt of wheat gives foul smell in the field due to presence of volatile compound
Correct Answer
(B) Trimethyl amine
Explanation
Solution: 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.
[#943] Tiechoic acid is present in
Correct Answer
(A) Gram +ve bacteria
Explanation
Solution: 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.
[#944] 'Buck eye rot' is a disease of which crop
Correct Answer
(A) Water chestnut
Explanation
Solution: '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.
[#945] Rock phosphate has chemical composition
Correct Answer
(B) Ca 3 (PO 4 ) 2
Explanation
Solution: Rock phosphate has a chemical composition Ca 3 (PO 4 ) 2 . It is a calcium salt of phosphoric acid with the chemical formula Ca 3 (PO 4 ) 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.