Plant Pathology - Study Mode
[#201] Photorespiration in C 3 plants starts from
Correct Answer
(B) Phosphoglycolate
Explanation
Solution: Photorespiration in C 3 plants starts from Phosphoglycolate. Photorespiration refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. The oxygenation reaction of RuBisCO is a wasteful process because 3-phosphoglycerate is created at a lower rate and higher metabolic cost compared with RuBP carboxylase activity. PGA is the normal product of carboxylation and productively enters the Calvin cycle. Phosphoglycolate, however, inhibits certain enzymes involved in photosynthetic carbon fixation.
[#202] Propoxur is
Correct Answer
(A) Carbamate
Explanation
Solution: Propoxur is Carbamate. Propoxur (Baygon) is a carbamate non-systemic insecticide introduced in 1959 with a fast knockdown and long residual effect used against the turf, forestry, and household pests and fleas. Carbamate insecticides kill insects by irreversibly inactivating the enzyme acetylcholinesterase.
It is also used in pest control for other domestic animals, Anopheles mosquitoes, ants, gypsy moths, and other agricultural pests.
[#203] Citrus greening caused by the
Correct Answer
(A) Fastidious bacteria
Explanation
Solution: Citrus greening is caused by Fastidious bacteria. Citrus greening disease is a disease of citrus caused by a vector-transmitted pathogen. The causative agents are motile bacteria. The causative agents are fastidious phloem-restricted, Gram-negative bacteria in the gracilicutes clade. The disease is vectored and transmitted Needham made the 1 st report of nematode associated with plant disease in 1943 by the Asian citrus psyllid, Diaphorina citri , and the African citrus psyllid, Trioza erytreae , also known as the two-spotted citrus psyllid.
[#204] Who made the 1 st report of nematode associated with plant disease in 1943?
Correct Answer
(C) Needham
Explanation
Solution: Needham made the 1 st report of nematode associated with plant disease in 1943. Turbevil Needham accidentally recorded the first plant parasitic nematode when he crushed one of the shrunken and blackened wheat grains and observed “Aquatic worms, Eels, or Serpents, which they very much resemble.” He named it Vibrio tritici. Later this nematode was rightly named Anguina tritici by Steinbuch. From 1750 to the early 1900s, Nematology research continued to be descriptive and taxonomic, focusing primarily on free-living nematodes, and plant and animal parasites.
[#205] Development of female gametophyte directly from megaspore mother cell without meiosis is called
Correct Answer
(B) Apospory
Explanation
Solution: Development of female gametophyte directly from megaspore mother cell without meiosis is called Apospory. Apospory is the development of 2n gametophytes, without meiosis and spores, from vegetative, or nonreproductive, cells of the sporophyte. Apospory develops in pteridophytes that have a mineral nutrition shortage due to insufficient minerals in the soil.