Plant Pathology - Study Mode
[#736] Glycolate accumulates in chloroplasts when there is
Correct Answer
(D) Low CO 2
Explanation
Solution: Glycolate accumulates in chloroplasts when there is Low CO 2 . glycolate is produced during photosynthesis as a result of a reaction between a 2-carbon piece derived from a sugar phosphate and an oxidant generated by the photochemical act. Glycolate leads to the inhibition of metabolic processes that impair CO 2 assimilation. Furthermore, glycolate feeding to Arabidopsis roots strongly reduces root growth indicating toxic effects not related to photosynthetic processes.
[#737] Uniformly sweet taste of Tea or Coffee is due to
Correct Answer
(B) Diffusion
Explanation
Solution: Uniformly sweet taste of Tea or Coffee is due to Diffusion. Diffusion is the net movement of anything generally from a region of higher concentration to a region of lower concentration. The central idea of diffusion, however, is common to all of these: a substance or collection undergoing diffusion spreads out from a point or location at which there is a higher concentration of that substance or collection.
[#738] Which antibiotic was first time demonstrated by Fleming (1929)
Correct Answer
(A) Penicillin
Explanation
Solution: Penicillin antibiotic was first time demonstrated by Fleming (1929). Scottish physician Alexander Fleming was the first to experimentally discover that a Penicillium mould secretes an antibacterial substance and the first to concentrate the active substance involved, which he named penicillin. He concluded that the mould was releasing a substance that was inhibiting bacterial growth, and he produced culture broth of the mould and subsequently concentrated the antibacterial component. After testing against different bacteria, he found that the mould could kill only specific bacteria.
[#739] Rickettsia can be diagnosed by
Correct Answer
(A) Giema stain
Explanation
Solution: Rickettsia can be diagnosed by Giemsa stain. The rickettsiae are a diverse collection of obligately intracellular Gram-negative bacteria found in ticks, lice, fleas, mites, chiggers, and mammals. They include the genera Rickettsiae, Ehrlichia, Orientia and Coxiella. Giemsa stain named after German chemist and bacteriologist Gustav Giemsa is a nucleic acid stain used in cytogenetics and for the histopathological diagnosis of malaria and other parasites. Giemsa stain is used in Giemsa banding, commonly called G-banding, to stain chromosomes and is often used to create a karyogram (chromosome map). It can identify chromosomal aberrations such as translocations and rearrangements.
[#740] Covered smut of barley (Caused by Ustilago hordei) is/are
Correct Answer
(B) Externally seed borne
Explanation
Solution: Covered smut of barley (Caused by Ustilago hordei) is Externally seed borne. Covered smut of barley is caused by the fungus Ustilago hordei. The disease is found worldwide and it is more extensively distributed than either loose smut or false loose smut. Kernels of infected plants are replaced by masses of dark brown smut spores. Smutted heads are hard and compact. Infected plants may be stunted. Infection is seed-borne within the seed, the fungus penetrating the endosperm while the grain is being formed. Infected seeds give rise to systemically infected plants. The mycelium advances through the host tissue and becomes established behind the growing point.