Plant Pathology - Study Mode
[#541] In hexose monophosphate shunt, number of molecules of carbon dioxide evolved is
Correct Answer
(C) More than glycolysis
Explanation
Solution: In hexose monophosphate shunt, number of molecules of carbon dioxide evolved is more than in glycolysis. Hexose monophosphate shunt and the HMP Shunt) is a metabolic pathway parallel to glycolysis. It generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides. In HMP, 6 carbon dioxide molecules are produced whereas in glycolysis no CO 2 molecule is produced.
[#542] Light energy is converted into chemical energy in the presence of
Correct Answer
(A) Chloroplasts
Explanation
Solution: Light energy is converted into chemical energy in the presence of Chloroplasts. The phenomenon involved in conversion of light energy I to chemical energy in the chloroplasts is termed Photosynthesis. In plants and algae, photosynthesis takes place in organelles called chloroplasts. A typical plant cell contains about 10 to 100 chloroplasts.
[#543] Select the systemic fungicides
Correct Answer
(D) All of these
Explanation
Solution: Pyrimidines, Triazoles and Metalaxyl are the systemic fungicides. A Systemic fungicide may be defined as a fungicidal compound that is readily translocated as such in the plant, rendering the tissues penetrated toxic to fungi. New pyrimidine derivatives were synthesized and their antifungal activities were evaluated in vitro against fourteen phytopathogenic fungi. Triazole fungicides (TFs) are systemic pesticides, which are widely used to prevent fungal diseases in agriculture, thereby protecting vegetables, fruits and crops. Metalaxyl is a systemic fungicide used to control plant diseases caused by Oomycete fungi. Its formulations include granules, wettable powders, dust, and emulsifiable concentrates.
[#544] Which of the following nutrient elements is responsible for resistance to plant disease?
Correct Answer
(D) K
Explanation
Solution: Potassium is the nutrient element is responsible for resistance to plant disease. Potassium is associated with the movement of water, nutrients and carbohydrates in plant tissue. It's involved with enzyme activation within the plant, which affects protein, starch and adenosine triphosphate (ATP) production. The production of ATP can regulate the rate of photosynthesis. Natural disease resistance mechanisms can be enhanced by plant nutrients like potassium.
[#545] Potato virus diseases are spread by
Correct Answer
(A) Aphids
Explanation
Solution: Potato virus diseases are spread by Aphids. Aphids are sap-sucking insects and have piercing, sucking mouthparts. Their mouthparts include a needle-like stylet that allows the aphid to access and feed on the contents of plant cells. Potato virus is spread naturally in a non-persistent manner by many aphid species and can be mechanically transmitted. The virus is transmitted when an aphid initially probes the plants. The most important viruses transmitted by aphids to potatoes in Scotland are potato leaf roll virus (PLRV), potato virus Y (PVYO and PVYN (veinal necrosis)) and potato virus A (PVA).