Plant Pathology - Study Mode

[#301] In plants. nitrate is reduced to ammonia state in two steps. In second step. electrons are donated by
Correct Answer

(C) Ferredoxin

Explanation

Solution: In plants, nitrate is reduced to an ammonia state in two steps. In the second step, electrons are donated by Ferredoxin. First, nitrate is reduced to nitrite in the cytoplasm by nitrate reductase and then nitrite is reduced to ammonia by nitrite reductase in the chloroplasts. In chloroplasts, Fe 2 S 2 ferredoxins function as electron carriers in the photosynthetic electron transport chain and as electron donors to various cellular proteins, such as glutamate synthase, nitrite reductase, sulphite reductase, and the cyclase of chlorophyll biosynthesis.

[#302] Which one of the following is the primary source of inoculum for stem rust of water for southern and central India
Correct Answer

(A) Uredospores produced in Nilgiri and Palney hills during off season of the crop

Explanation

Solution: Uredospores produced in Nilgiri and Palney hills during the off-season of the crop are the primary source of inoculum for stem rust of water for southern and central India. Uredospore is one of the thin-walled spores that are produced by uredinial hyphae and spread the fungus vegetatively. Since the urediniospores are produced on the cereal host and can infect the cereal host, the infection can pass from one year's crop to the next without infecting the alternate host. In other cases the fungus passes between winter wheat and spring wheat, meaning that it has a cereal host all year round. Since the urediniospores are wind dispersed, this can occur over large distances.

[#303] The Bordeaux mixture was first time used for the control of
Correct Answer

(A) Downey mildew of grape vines

Explanation

Solution: The Bordeaux mixture was first time used for the control of Downey mildew of grape vines.
Bordeaux mixture is a mixture of copper(II) sulphate (CuSO 4 ) and quicklime (CaO) used as a fungicide. It is used in vineyards, fruit farms and gardens to prevent infestations of downy mildew, powdery mildew and other fungi. It is sprayed on plants as a preventive treatment, but its mode of action is ineffective after a fungus has become established.

[#304] Causal organism of smut of bajra is
Correct Answer

(D) Tolyposporium penicillariae

Explanation

Solution: Causal organism of smut of bajra is Tolyposporium penicillariae. Tolyposporium penicillariae, the causal agent of pearl millet smut. Sporeballs of Tolyposporium penicillariae varied from circular to near-polyhedral and measured 42-325 × 50-175 μm. The number of teliospores aggregated in balls varied from 200 to 1400. Teliospores were mostly circular and measured 7-12 μm diam.

[#305] PS II performs
Correct Answer

(B) Photolysis of water

Explanation

Solution: PS II performs Photolysis of water. Photosystem II is the first protein complex in the light-dependent reactions of oxygenic photosynthesis. It is located in the thylakoid membrane of plants, algae and cyanobacteria. The energized electrons are replaced by oxidizing water to form hydrogen ions and molecular oxygen. By replenishing lost electrons with electrons from the splitting of water, photosystem II provides the electrons for all of the photosynthesis to occur.