FREE NEET Biology Practice MCQ Test: Mineral Nutrition Exercise 4 Questions Answers With Detailed Explanations [PDF]

Answer: (b)

Answer: (c)

Answer: (c)

Some fungi form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza. The fungal symbiont in these associations absorbs phosphorus from soil and passes it to the plant. Plants having such associations show other benefits also, such as resistance to root-borne pathogens, tolerance to salinity and drought, and an overall increase in plant growth and development.

Answer: (a)

Answer: (b)

Answer: (a)

Zinc is available to the plants for absorption in the divalent form. The availability of soil decreases when the pH of soil shifts towards alkaline side. Zinc may form zinc phosphate in the soil which is insoluble and in that case, it is not available to the plants. It is essential for synthesis of tryptophan amino acid, which forms IAA (Indole Acetic Acid) its deficiency causes chlorosis of older leaves.

Answer: (b)

Answer: (b)

Answer: (d)

Sulphur is present in two vitamins of B complex, thiamine and biotin. Biotin is important to hair. It is normally found in protein foods, such as eggs, lettuce, sprouts, etc.

Answer: (b)

The deficiency symptoms tend to appear first in the young tissues whenever the elements are relatively immobile and are not transported out the mature organs, for example, elements like sulphur and calcium are a part of the structural component of the cell and hence are not easily released. The deficiency symptoms of nitrogen, potassium and magnesium are visible first in the senescent leaves.

Answer: (b)

Answer: (c)

Molybdenum is a micronutrient which is required in very minute amount by the plants. It is responsible for nodulation in legumes. It is part of nitrate reductase enzyme which helps in nitrogen fixation.

Answer: (c)

Answer: (a)

Magnesium is an essential mineral nutrient for life and is present in every cell type in every organism. In plants, magnesium is necessary for synthesis of chlorophyll and photosynthesis. It is a constituent of the ring structure of the chlorophyll and helps to maintain the ribosome structure.

Answer: (c)

Micronutrients or trace elements are essential elements required by plants in traces only less than 10 mmole $kg^{–1}$ of dry matter. These are eight in numbers (Zn, Mn, B, Cu, Mo, Cl, Ni, Fe).

Answer: (c)

Certain species of cyanobacteria (Nostoc) possess some special cells called heterocysts which occur in terminal, basal and intercalary positions. Heterocysts are yellowish in colour and contents are homogenous. Heterocysts are now known as sites of nitrogen fixation. Atmospheric nitrogen is made available in the form of ammonia by cyanobacteria.

Answer: (c)

Iron is absorbed by plants in the form of ferric ions.

Answer: (d)

Answer: (b)

Answer: (c)

Nitrifying bacteria involves the oxidation of ammonia to nitrates through nitrites called nitrification. Nitrite bacteria (Nitrosomonas and Nitrococcus) convert ammonia to nitrites whereas, nitrate bacteria (Nitrobacter and Nitrocystis) convert nitrite to soluble nitrates.