Plant Pathology - Study Mode
[#471] Scab is a result of
Correct Answer
(A) Hyperplasia
Explanation
Solution: Scab is a result of Hyperplasia. Sebaceous hyperplasia is a skin condition that becomes more common with age. It's caused when your sebaceous oil glands produce too much oil, which can be trapped under your skin and cause bumps. This creates shiny bumps on the skin, especially on the face. Scab is a mass of dried blood that forms over a part of the body where the skin has been cut or broken, it is sometimes caused as a result of hyperplasia.
[#472] The term virus was first time coined by
Correct Answer
(B) Beijerinck
Explanation
Solution: The term virus was first time coined by Beijerinck. Beijerinck, in 1898, was the first to call 'virus', the incitant of the tobacco mosaic. Martinus Willem Beijerinck was a Dutch microbiologist and botanist who was one of the founders of virology and environmental microbiology. He showed that the inoculant was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria.
[#473] When day light hours are increased, the rate of photosynthesis
Correct Answer
(C) Remains unchanged
Explanation
Solution: When daylight hours are increased, the rate of photosynthesis remains unchanged. "When a process is conditioned as to its rapidity by several separate factors the rate of the process is limited by the pace of the slowest factor." Limiting factors are not limited to the condition of the species. When during the day, light hours are increased, it does not affect the rate of photosynthesis much, therefore, the rate of photosynthesis remains unchanged.
[#474] Which race of Ralstonia solanacearum cause disease in potato?
Correct Answer
(B) Race II
Explanation
Solution: Race II of Ralstonia solanacearum cause disease in potato. Ralstonia solanacearum is a soil-borne bacterium causing the widespread disease known as bacterial wilt. Ralstonia solanacearum is also the causal agent of Moko disease of bananas and brown rot of potato.
[#475] Thylakoids possess photosynthetic units called
Correct Answer
(A) Quantasomes
Explanation
Solution: Thylakoids possess photosynthetic units called Quantasomes. Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in a paracrystalline array on the surface of thylakoid discs in chloroplasts. They are composed of lipids and proteins that include various photosynthetic pigments and redox carriers. Quantasomes were first identified by Roderic B. Park in 1962. Each quantasome contains about 230 - 250 chlorophyll molecules and 50 molecules of carotenoids.