Plant Pathology - Study Mode

[#231] Early blight of potato is
Correct Answer

(A) Soil borne disease

Explanation

Solution: Early blight of potatoes is Soil borne disease. Early blight and late blight are terrible soil-borne diseases. Early blight also called Alternaria is a soil-borne fungal vector with the main two species being Alternaria solani and Alternaria alternata. The disease affects leaves, stems and tubers and can reduce yield, tuber size, storability of tubers, quality of fresh-market and processing tubers and marketability of the crop. Alternaria species cause dramatic leaf losses in growing potato crops which in turn can reduce yields by up to 30%.

[#232] Flashing light experiments on photosynthesis were performed by
Correct Answer

(D) Emerson and Arnold

Explanation

Solution: Flashing light experiments on photosynthesis were performed by Emerson and Arnold. Emerson and William Arnold found that "the yield per flash reached a maximum when just 1 out of 2500 chlorophylls absorbed a quantum". Next, in 1939, Emerson demonstrated that between 8 and 12 quanta of light were needed to produce one molecule of oxygen.

[#233] Micronutrient absorbed by foliage is
Correct Answer

(A) Zinc

Explanation

Solution: Micronutrient absorbed by foliage is Zinc. Zinc is an important component of various enzymes that are responsible for driving many metabolic reactions in all crops. Growth and development would stop if specific enzymes were not present in plant tissue. Spray the plant with kelp extract or a micro-nutrient foliar spray that contains zinc. Foliar sprays provide zinc for plants where it is needed most and the rate at which they recover is amazing.

[#234] A totipotent cell means
Correct Answer

(A) An undifferentiated cell capable of developing into a system or entire plant

Explanation

Solution: A totipotent cell means an undifferentiated cell capable of developing into a system or entire plant. A single cell can divide and produce all the differentiated cells in an organism, including extraembryonic tissues. Totipotent cells formed during sexual and asexual reproduction include spores and zygotes.

[#235] In plants buckling, puckering and blistering symptoms are produced by
Correct Answer

(C) Viruses

Explanation

Solution: In plants buckling, puckering and blistering symptoms are produced by Viruses. Plant viruses are made up of a strand of nucleic acid (DNA or RNA) surrounded by a protein sheath. Local symptoms are physiological or structural changes within a limited area of host tissue, such as leaf spots, galls, puckering, buckling and cankers. Symptoms of virus infection include necrotic spots, abnormal dark green and light green mosaic and mottling of leaves, growth distortion, stunting, ring patterns or bumps on plant foliage, and abnormal flower coloration and formation.