Plant Pathology - Study Mode

[#431] In angiosperms the number of meiotic division required to produce 100 microspores is
Correct Answer

(D) 25

Explanation

Solution: In angiosperms the number of meiotic divisions required to produce 100 microspores is 25. Male gametes are formed by the process of microsporogenesis, and in this, 1 cycle leads to the formation of 4 pollen grains. For 100 microspores, $$frac{{100}}{4}$$ = 25 cycles of meiosis will be done.

[#432] Photosystem has main light harvesting pigments
Correct Answer

(A) Chlorophyll a-660, chI. a-670, chI. a-680, chI. a-690, chI. a-700

Explanation

Solution: Photosystem has main light harvesting pigments, Chlorophyll a-660, chI. a-670, chI. a-680, chI. a-690, chI. a-700. Chlorophyll a is a specific form of chlorophyll used in oxygenic photosynthesis. It absorbs most energy from wavelengths of violet-blue and orange-red light, and it is a poor absorber of green and near-green portions of the spectrum. Chlorophyll a also transfers resonance energy in the antenna complex, ending in the reaction center where specific chlorophylls P680 and P700 are located.

[#433] Gram negative bacteria are included under
Correct Answer

(B) Gracilicutes

Explanation

Solution: Gram negative bacteria are included under Gracilicutes. It is a gram-negative clade that branched off from other bacteria just before the evolutionary loss of the outer membrane or capsule, and just after the evolution of flagella. The gram-negative bacteria include the model organism Escherichia coli, as well as many pathogenic bacteria, such as Pseudomonas aeruginosa, Chlamydia trachomatis, and Yersinia pestis.

[#434] Stem cuttings are commonly used in propagation of
Correct Answer

(C) Rose

Explanation

Solution: Stem cuttings are commonly used in propagation of Rose. Roses can be grown successfully from cuttings and will grow to make good flowering plants. Cut a section of the stem between 6 and 8 inches long, and remove the withered flower. Remove all the leaves or remove all but the top leaves, then replant them. The stem will then begin to root and will establish itself as a new plant.

[#435] The enzyme that catalyses carbon dioxide fixation in C 4 plants is
Correct Answer

(B) PEP carboxylase

Explanation

Solution: The enzyme that catalyzes carbon dioxide fixation in C 4 plants is PEP carboxylase. PEP carboxylase, which is located in the mesophyll cells, is an essential enzyme in C 4 plants. In hot and dry environments, carbon dioxide concentrations inside the leaf fall when the plant closes or partially closes its stomata to reduce water loss from the leaves.