Agriculture Microbiology MCQ tribhuvan University 7

61. ………..percentage of plant material and ………….percentage of plant protein is composed of sulfur
a. 1,2 b. 0.5 , 1 c. 2 , 3 d. 3 , 4.5
62. lignin metabolism is triggered by……….
a. N, S, or C starvation b.Supplement of N and C c. addition of cellulose and hemicellulose d. supplement of C, N and S
63. Lignin ………cellulose and hemicellulose decomposition.
a. Increases b. decreases c. acclerates d.does not alter
64. …….. of soil microbial population solubilizes phosphorus.
a. 10% b. 20% c 40% d. 50%
65. mechanism of phosphorus solubilization is by
a. chelation b. iron reduction c. acid production d. all of the above
66. in a food chain consisting of the following, which acts as the decomposer
a. Protozoa b. Algae c. helminth d. fungi
67. …………forms stem nodules.
a. Azorhizobium b. Bradyrhizobium c. Rhizobium d. cyanobacteria
68. ……..have been used for centuries to enrich ride paddies
a. Anabaena azollae b. Frankia c. Azospirillum lipoferum d. rhizobium
69. The size of the minerals clay, silt and sand is respectively…………..
a. 2µm, 0.002-0.05 mm, 0.05-2.0 mm b. 0.002-0.05 mm, 2µm, 0.05-2.0 mm
c. 0.05-2.0 mm, 2µm, ≥2.0 mm d. 2µm, 0.05-2.0 mm, 0.002-0.05mm
70. which region of the soil profile is also called surface soil
a. C horizon b. A horizon c. O horizon d. B horizon