Plant Pathology - Study Mode
[#86] The perfect (sexual) stage not seen in
Correct Answer
(D) Deuteromycotina
Explanation
Solution: The perfect (sexual) stage is not seen in Deuteromycotina. The fungi imperfecti or imperfect fungi are fungi that do not fit into the commonly established taxonomic classifications of fungi that are based on biological species concepts or morphological characteristics of sexual structures. They are known as imperfect fungi because only their asexual and vegetative phases are known. They have an asexual form of reproduction, meaning that these fungi produce their spores asexually, in a process called sporogenesis.
[#87] Photo-oxidation or photolysis of water (in photosynthesis) occurs in association of
Correct Answer
(C) PS II
Explanation
Solution: Photo-oxidation or photolysis of water (in photosynthesis) occurs in association with PS II. 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. The hydrogen ions (protons) generated by the oxidation of water help to create a proton gradient that is used by ATP synthase to generate ATP.
[#88] Protoplasmic streaming theory of translocation of organic solutes was first proposed by
Correct Answer
(C) de Vries
Explanation
Solution: The protoplasmic streaming theory of translocation of organic solutes was first proposed by de Vries. Hugo Marie de Vries was a Dutch botanist and one of the first geneticists. He is known chiefly for suggesting the concept of genes. Cytoplasmic streaming, also called protoplasmic streaming, is the movement of the fluid substance (cytoplasm) within a plant or animal cell. The motion transports nutrients, proteins, and organelles within cells.
[#89] Protochlorophyll differs from chlorophyll in lacking
Correct Answer
(B) 2 hydrogen atoms in one of its pyrrole rings
Explanation
Solution: Protochlorophyll differs from chlorophyll in lacking 2 hydrogen atoms in one of its pyrrole rings. Protochlorophyll is a green magnesium-containing pigment that is present in etiolated leaves and seedlings which develop in the dark and is converted to chlorophyll by reduction under the influence of light. Photochlorophyll lacks two hydrogens at the 7 and 8 positions at the porphyrin part of the pyrrole ring. Protochlorophyll has been detected in dark-grown roots of several species of plants from ferns to angiosperms.
[#90] The fungus of Drechslera oryzae produces toxins which are highly toxic to rice seedling name of such toxin is
Correct Answer
(D) None of these
Explanation
Solution: The fungus of Drechslera oryzae produces toxins that are highly toxic to rice seedling name of such toxin is ophiobolins. Neither ABA, trimethyl amine nor isobutylene. Drechslera oryzae causes brown leaf spot disease in rice (Oryza sativa L.). This fungal pathogen produces a series of ophiobolins that cause some of the characteristic symptoms of the disease when applied to rice leaves at 10 -4 and 10 -5 M.