Plant Pathology - Study Mode
[#551] Outbreak of coffee rust in 1870 was marked in which country?
Correct Answer
(D) Srilanka
Explanation
Solution: The outbreak of coffee rust in 1870 was marked in Srilanka. Hemileia vastatrix is a multicellular basidiomycete fungus that causes coffee leaf rust (CLR), a disease affecting the coffee plant. Coffee serves as the obligate host of coffee rust, that is, the rust must have access to and come into physical contact with coffee to survive. Rust was first reported in the major coffee-growing regions of Sri Lanka. The causal fungus was first fully described by the English mycologist Michael Joseph Berkeley.
[#552] The bacterium containing yellow pigment is
Correct Answer
(A) Xanthomonas
Explanation
Solution: The bacterium containing yellow pigment is Xanthomonas. Xanthomonadins are a unique class of carotenoid-like pigments produced by members of the phytopathogenic genus Xanthomonas. These pigments are brominated, aryl-polyene, yellow, water-insoluble pigments that are associated exclusively with the outer membrane of the bacterial cell wall.
[#553] In Maize, mesophyll cells perform photosynthetic cycle
Correct Answer
(A) C 4
Explanation
Solution: In Maize, mesophyll cells perform photosynthetic cycle C 4 . C 4 carbon fixation is one of three known photosynthetic processes of carbon fixation in plants. Like many other plants, maize is one of the C 4 plants, where the photosynthetic cycle is performed in mesophyll cells. C 4 leaves generally differentiate into two partially isolated compartments called mesophyll cells and bundle-sheath cells. CO 2 is initially fixed in the mesophyll cells by the enzyme PEP carboxylase which reacts the three-carbon phosphoenolpyruvate (PEP) with CO 2 to form the four-carbon oxaloacetic acid (OAA).
[#554] Soft rot of squash is caused by
Correct Answer
(A) Choanephora parasitica
Explanation
Solution: Soft rot of squash is caused by Choanephora parasitica. Choanephora is a genus of Zygomycota fungi. Choanephora species are known as plant pathogens. Soft rot also known as Choanephora or wet rot is a disease most commonly found on summer squash under wet conditions. This disease also infects other cucurbits including pumpkins and zucchini. The fungus can infect flowers or fruit during prolonged wet periods.
[#555] Carbon dioxide assimilation occurs through
Correct Answer
(B) Calvin cycle
Explanation
Solution: Carbon dioxide assimilation occurs through the Calvin cycle. The Calvin cycle reactions fix CO 2 from the environment to build carbohydrate molecules. An enzyme, RuBisCO, catalyzes the fixation reaction, by combining CO 2 with RuBP. Calvin cycle is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose.