Mineral Nutrition

In which of the following forms is iron absorbed by plants?

1. Ferrous
2. Both ferric and ferrous
3. Ferric
4. Free element

In which of the following all three are macronutrients?

1. Molybdenum, magnesium, manganese
2. Nitrogen, phosphorus, sulphur
3. Boron, Zinc, manganese
4. Iron, copper, molybdenum

Which is essential for the growth of root tip?

1. Zn
2. Fe
3. Ca
4. Mn

The oxygen evolved during photosynthesis, comes from water molecules. Which one of the following pairs of elements is involved in this reaction?

1. Magnesium and Molybdenum
2. Magnesium and Chlorine
3. Manganese and chlorine
4. Manganese and Potassium

During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by

1. carotene
2. cytochrome
3. leghaemoglobin
4. xanthophyll.

Minerals known to be required in large amounts for plant growth include

1. potassium, phosphorus, selenium, boron
2. magnesium, sulphur, iron, zinc
3. phosphorus, potassium, sulphur, calcium
4. calcium, magnesium, manganese, copper.

Deficiency symptoms of nitrogen and potassium are visible first in

1. senescent leaves
2. young leaves
3. roots
4. buds.

The first stable product of fixation of atmospheric nitrogen in leguminous plants is

1. NO3-
2. glutamate
3. NO2-
4. ammonia.

Which two distinct microbial processes are responsible for the release of fixed nitrogen as dinitrogen gas (N2) to the atmosphere ?

1. Anaerobic ammonium oxidation, and denitrification
2. Aerobic nitrate oxidation, and nitrite reduction
3. Enteric fermentation in cattle, and nitrogen fixation by Rhizobium in root nodules of legumes
4. Decomposition of organic nitrogen, and conversion of dinitrogen to ammonium compounds

Which of the following elements is a constituent of biotin?

1. Magnesium
2. Calcium
3. Phosphorus
4. Sulphur