Mineral Nutrition

Thiobacillus is a group of bacteria helpful in carrying out :

1. Nitrification
2. Denitrification
3. Nitrogen fixation
4. Chemoautotrophic fixation

Which of the following elements is responsible for maintaining turgor in cells?

1. Sodium
2. Calcium
3. Magnesium
4. Potassium

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.