Mineral Nutrition

Which micronutrient is required for splitting of water molecule during photosynthesis?

1. Molybdenum
2. Magnesium
3. Copper
4. Manganese

Which one of the following produces nitrogen fixing nodules on the roots of Alnus?

1. Rhizobium
2. Frankia
3. Rhodospirillum
4. Beijerinckia

Which of the following pair represents free living nitrogen fixing aerobic bacteria?

1. Pseudomonas and Thiobacillus
2. Rhizobium and Frankia
3. Azotobacter and Beijernickia
4. Anabaena and Rhodospirillum

Which of the following protects nitrogenase inside the root nodule of a leguminous plant?

1. Glutamate dehydrogenase
2. Catalase
3. leg haemoglobin
4. Transaminase

The product(s) of reaction catalyzed by nitrogenase in root nodules of leguminous plants is/are

1. Ammonia alone
2. Nitrate alone
3. Ammonia and oxygen
4. Ammonia and hydrogen

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.

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

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

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

For its action, nitrogenase requires

1. high input of energy
2. light
3. Mn2+
4. super oxygen radicals

Which one of the following is wrong statement?

1. Anabaena and Nostoc are capable of fixing nitrogen in free-living state also.
2. Root nodule forming nitrogen fixers live as aerobes under free-living conditions.
3. Phosphorus is a constituent of cell membranes, certain nucleic acids and all proteins.
4. Nitrosomonas and Nitrobacter are chemo-autotrophs.

Best defined function of manganese in green plants is

1. photolysis of water
2. Calvin cycle
3. nitrogen fixation
4. water absorption

Which one of the following is correctly matched?

1. Passive transport of nutrients – ATP
2. Apoplast – Plasmodesmata
3. Potassium – Readily immobilisation
4. Bakane of rice seedlings – F. Skoog

Which one of the following is essential for photolysis of water?

1. Copper
2. Manganese
3. Boron
4. Zinc

Which one of the following is not an essential mineral element for plants while the remaining three are?

1. Iron
2. Manganese
3. Cadmium
4. Phosphorus

Which one of the following elements in plants is not remobilised?

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

Nitrifying bacteria

1. oxidize ammonia to nitrates
2. convert free nitrogen to nitrogen compounds
3. convert proteins into ammonia
4. reduce nitrates to free nitrogen

The function of leghaemoglobin in the root nodules of legumes is

1. inhibition of nitrogenase activity
2. oxygen removal
3. nodule differentiation
4. expression of nif gene

Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation?

1. Leghaemoglobin scavenges oxygen and is pinkish in colour.
2. Nodules act as sites for nitrogen fixation.
3. The enzyme nitrogenase catalyses the conversion of atmospheric N2 to NH3.
4. Nitrogenase is insensitive to oxygen.

Study the cycle shown below and select the option which gives correct words for all the four blanks A, B, C and D. [figure]

1. array|l|l|l|l| A & B & C & D \ Nitrification & Ammonification & Animals & Plants \ array
2. array|l|l|l|l| A & B & C & D \ Denitrification & Ammonification & Plants & Animals \ array
3. array|l|l|l|l| A & B & C & D \ Nitrification & Denitrification & Animals & Plants \ array
4. array|l|l|l|l| A & B & C & D \ Denitrification & Nitrification & Plants & Animals \ array

One of the free-living, anaerobic nitrogen-fixer is

1. Beijerinckia
2. Rhodospirillum
3. Rhizobium
4. Azotobacter