Select the mismatch:
1. Rhodospirillum - Mycorrhiza
2. Anabaena - Nitrogen fixer
3. Rhizobium - Alfalfa
4. Frankia - Alnus
Hydroponics refers to growing plants in
1. Macronutrients culture medium
3. Solution of mineral nutrients
Select the incorrect statement w.r.t. criteria of essentiality of minerals.
1. Element must be necessary for normal growth and reproduction
2. Element must be replaceable by another element
3. Disorders caused by the absence/deficiency of an element can be corrected only by adding that specific element
4. Element must be directly involved in plant metabolism
A macronutrient which is component of all organic compounds but is not a mineral element is
Mark the correct sequence of steps for the development of root nodules in legumes.
a. Formation of infection thread.
b. Division of cortical and pericyclic cells.
c. Curling of root hairs.
d. Leghaemoglobin synthesis.
34. Match the following and choose the correct combination from the options given.
Column I Column II
a. Potassium (i) Germination of pollen grains
b. Molybdenum (ii) Involved in synthesis of auxin
c. Boron (iii) Involved in stomatal movement
d. Zinc (iv) Constituent of ferredoxin
e. Sulphur (v) Component of nitrate rèductase
1. a(iii), b(iv), c(ii), d(i), e(v)
2. a(iii), b(v), c(i), d(ii), e(iv)
3. a(i), b(ii), c(iii), d(iv), e(v)
4. a(ii), b(iii), c(v), d(i), e(iv)
How many ATP are required for the formation of one molecule of NH3 by the nitrogenase enzyme?
(a) Moderate decrease or increase of micronutrients causes deficiency and toxicity symptoms respectively.
(b) Excess of manganese causes toxicity of iron, calcium and molybdenum.
(c) A macronutrient is said to be toxic when present below a critical concentration.
1. Only (a) is correct
2. Only (b) is correct
3. (b) & (c) are correct
4. (a) & (c) are correct
Movement of electrolytes through the roots is generally
1. Against electro chemical gradient and require energy
2. Along electro chemical gradient and does not require energy
3. A passive process
4. Dependent on aquaporins
During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by.
Minerals known to be required in large amounts for plant growth include.
1. Magnesium, sulphur, iron, zinc
2. Phosphorus, potassium, sulphur, calcium
3. Calcium, magnesium, manganese, copper
4. Potassium, phosphorus, selenium, boron
Deficiency symptoms of nitrogen and potassium are visible first in.
1. Senescent leaves
2. Young leaves
The first stable product of fixation of atomspheric nitrogen in leguminous plants is:
Which one of the following is correctly matched?
1. Potassium - Readily mobilization
2. Bakane of rice seedings - F.Skoog
3. Passive transport of nutrients - ATP
4. Apoplast - Plasmodesmata
Best defined function of Manganese in green plants is
1. Nitrogen fixation
2. Water absorption
3. Photolysis of water
4. Calvin cycle
1. Reduce nitrates to free nitrogen
2. Oxidize ammonia to nitrates
3. Convert free nitrogen to nitrogen compounds
4. Convert proteins into ammonia
Which one of the following elements in plants is not remobilised?
A prokaryotic autotrophic nitrogen fixing symbiont is found in.
Which one of the following helps in absorption of phosphorus from soil by plants?
Which one of the following is not an essential mineral element for plants while the remaining three are?
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
4. Nitrogenase is insensitive to oxygen
An element playing important role in nitrogen fixation is
One of the free-living, anaerobic nitrogen-fixer is
Which one of the following statements is correct?
1. At present it is not possible to grow maize without chemical fertilizers.
2. Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies.
3. Both Azotobacter and Rhizobium fix atmospheric nitrogen in root nodules of plants.
4. Cyanobacteria such as Anabaena and Nostoc are important mobilizers of phosphates and potassium for plant nutrition in soil.
About 98 percent of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and:
1. Calcium and phosphorous
2. Phosphorus and sulphur
3. Sulphur and magnesium
4. Magnesium and sodium
The deficiencies of micro-nutrients, not only affects growth of plants but also vital functions such as photosynthetic and mitochondrial electron flow. Among the list given below, which group of three elements shall affect most, both photosynthetic and mitochondrial electron transport?
1. Cu, Mn, Fe
2. Co, Ni, Mo
3. Mn, Co, Ca
4. Ca, X, Na
Element necessary for the middle lamella is.
The most abundant element present in the plants is
Necrosis in crops is due to the deficiency of
1. Ca, K, S and Mo
2. N, K, S and Mo
3. N, S, Fe and Zn
4. Mg, S, Mn and Ca
When the plants are grown in magnesium deficient but urea rich soil, the symptoms expressed are
1. Yellowish leaves
2. Colourless petiole
3. Dark green leaves
4. Shoot apex die
Study the cycle shown below and select the option which gives correct words for all the four blanks A, B,C and D
1. A- Nitrification B- Ammonification C- Animals D- Plants
2. A- Dentrification B- Ammonification C- Plants D- Animals
3. A- Nitrification B- Dentrification C- Animals D- Plants
4. A- Dentrification B- Nitrification C- Plants D- Animals
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. Decomposition of organic nitrogen, and conversion of dinitrogen to ammonium compounds
4. Enteric fermentation in cattle, and nitrogen fixation by Rhizobium in root nodules of legumes