Plant Pathology - Study Mode
[#601] First product of photorespiration is
Correct Answer
(A) Phosphoglycolate
Explanation
Solution: The first product of photorespiration is Phosphoglycolate. Photorespiration refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. Addition of molecular oxygen to ribulose-1,5-bisphosphate produces 3-phosphoglycerate (PGA) and 2-phosphoglycolate (2PG, or PG). PGA is the normal product of carboxylation and productively enters the Calvin cycle. Phosphoglycolate, however, inhibits certain enzymes involved in photosynthetic carbon fixation.
[#602] Calvin cycle occurs in
Correct Answer
(D) Chloroplasts
Explanation
Solution: Calvin cycle occurs in Chloroplasts. The Calvin cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose. In plants, these reactions occur in the stroma, the fluid-filled region of a chloroplast outside the thylakoid membranes. These reactions take the products (ATP and NADPH) of light-dependent reactions and perform further chemical processes on them.
[#603] Number of Calvin cycles required to generate a molecule of hexose is
Correct Answer
(C) 6
Explanation
Solution: The number of Calvin cycles required to generate a molecule of hexose is 6. One turn of the Calvin cycle fixes one molecule of carbon dioxide. Thus, six turns of the Calvin cycle are required to produce one molecule of hexose sugar.
[#604] Who is considered founder of virology
Correct Answer
(A) Beijerinck
Explanation
Solution: Beijerinck is considered the founder of virology. Martinus Willem Beijerinck (1851 - 1931) first discovered a pathogen that was smaller than a bacterium. He called it a virus and is therefore the father of virology. Beijerinck was the first to recognize that viruses are reproducing entities that are different from other organisms. He also discovered new types of bacteria from soil and described biological nitrogen fixation.
[#605] Phytoplasma can be detected by
Correct Answer
(D) All of these
Explanation
Solution: Phytoplasma can be detected by DAPI stain, Dienes' stain, and ELISA. Phytoplasmas are obligate intracellular parasites of plant phloem tissue and of the insect vectors that are involved in their plant-to-plant transmission. The use of the polymerase chain reaction (PCR) and sequencing of the corresponding amplicons generated from the ribosomal RNA (rRNA) gene have allowed the identification and comparison of phytoplasma strains with techniques such as restriction fragment length polymorphism (RFLP) and phylogenetic analysis.