Soil Science - Study Mode
[#801] Leghaemoglobin percent in the root nodules of leguminous plants helps in nitrogen fixation by
Correct Answer
(A) Removing oxygen
Explanation
Solution: Leghaemoglbin percent in the root nodules of leguminous plants helps in nitrogen fixation by removing oxygen. Leghaemoglobin is produced as a result of a symbiotic association between bacteroid and plant. The major role of leghaemolglobin involves the protection of nitrogenase enzyme from denaturation, on exposure to the atmospheric concentration of oxygen, thus it helps in the supply of ample amount of oxygen to bacteria for respiration and protects enzyme by removing oxygen from there.
[#802] Which one of the following is commonly used as urease inhibitor
Correct Answer
(D) Phenol phosphorodiamidate
Explanation
Solution: Phenol phosphorodiamidate is most commonly used as a Urease inhibitor. Urease inhibitors are those chemical compounds that inhibit the functioning of the urease enzyme. The urease enzyme catalyzes the hydrolysis of urea, forming ammonia and carbon dioxide. These urease inhibitors are used as additives in synthetic urea fertilizer formulations to reduce the loss of fertilizer nitrogen from fields by slowing down the conversion of stable urea to volatile ammonia.
[#803] Which of the following soils have poor physical condition
Correct Answer
(B) Sodic
Explanation
Solution: Sodic soils have poor physical conditions. When the concentration of sodium ions predominates in the soil, it becomes sodic. The pH of sodic soils may be acidic, neutral, or alkaline. Sodic soils have a very poor structure which limits or prevents water infiltration and drainage. They tend to accumulate certain elements like boron and molybdenum in the root zone that may be toxic to plants.
[#804] Press Mud is a byproduct of which industry?
Correct Answer
(A) Sugar industry
Explanation
Solution: Press mud is a byproduct of the sugar industry. Press mud is the compressed sugar industry waste produced during the filtration of sugar cane juice. It serves as a good source of fertilizer. Sugar mills in India produce about 12 million tons of press mud as waste from the double sulphitation process.
[#805] Optimum temperature for mesophiles is
Correct Answer
(B) 35°C
Explanation
Solution: A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, with an optimum temperature of 35°C. these organisms play important role in the decomposition of organic matter and the mineralization of nutrients. Bacteria such as mesophiles are used in cheese making due to their role in fermentation.