Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

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Kerala Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Plus One Botany Mineral Nutrition One Mark Questions and Answers

Question 1.
Which one of the following roles is not characteristic of an essential element?
(a) being a component of biomolecules
(b) changing the chemistry of soil
(c) being a structural component of energy-related chemical compounds
(d) activation or inhibition of enzymes
Answer:
(b) changing the chemistry of soil

Question 2.
Which one of the following statements can best explain the term critical concentration of an essential element?
(a) essential element concentration below which plant growth is retarded.
(b) essential element concentration below which plant growth becomes stunted.
(c) essential element concentration below which plant remains in the vegetative phase.
(d) none of the above
Answer:
(b) essential element concentration below which plant growth becomes stunted.

Question 3.
During protein synthesis subunits of ribosomes are combined due to the presence of the particular element. Name it.
Answer:
Magnesium

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 4.
Deficiency symptoms of an element tend to appear first in young leaves.
It indicates that the element is relatively immobile. Which one of the following elemental deficiency would show such symptoms?
(a) sulphur
(b) Magnesium
(c) Nitrogen
(d) Potassium
Answer:
(a) sulphur

Question 5.
With regard to the Biological Nitrogen Fixation by Rhizobium in association with soybean, which one of the following statement/statements does not hold true.
(a) Nitrogenase may require oxygen for its functioning
(b) Nitrogenase is MO- Fe protein
(c) Leg-hemoglobin is a pink coloured pigment.
(d) Nitrogenase helps to convert N2 gas into two molecules of ammonia.
Answer:
(a) Nitrogenase may require oxygen for its functioning

Question 6.
Name the free-living microorganisms which can fix nitrogen.
Answer:
Azotobactor and Rhodospirillum

Question 7.
In what form do plants absorb molebdenum from the soil.
Answer:
Molybdate ions MoO22+

Question 8.
Mineral requirements of plants is explained by a method in the nutrient solution is Called ………. and it was demonstrated by ……….. for the first time.
Answer:
Hydroponics,Julius von sachs

Question 9.
Find the odd one out.
Boron, Copper, Zinc, Phosphorous
Answer:
Phosphorous

Question 10.
A plant cell when kept in a certain solution got plasmolysed. What was the nature of the solution?
Answer:
Hypertonic Solution.

Question 11.
Plants can be cultivated in water. Name the type of cultivation.
Answer:
Hydroponics

Question 12.
Find the odd one among the following Carbon, Manganese, potassium, Nitrogen
Answer:
Manganese

Question 13.
A farmer adds Azotobacter culture to the soil before sowing maize. Which mineral element is being replenished?
Answer:
Nitrogen

Question 14.
In the diagram below, Label the cell Ain Nostoc
Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img1
Answer:
Heterocyst

Question 15.
Which one of the following statements can best explain the term critical concentration of an essential element?
(a) essential element concentration below which plant growth is retarded.
(b) essential element concentration below which plant growth becomes stunted.
(c) essential element concentration below which plant remains in the vegetative phase.
(d) none of the above
Answer:
(a) essential element concentration below which plant growth is retarded.

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 16.
Deficiency symptoms of an element tend to appear first in young leaves. It indicates that the element is relatively immobile. Which elemental deficiency would show such symptoms?
Answer:
Sulphur or calcium

Question 17.
From where do plants receive hydrogen?
Answer:
Water absorbed by plants.

Plus One Botany Mineral Nutrition Two Mark Questions and Answers

Question 1.
Give example for

  1. Free-living N2 fixing bacteria.
  2. Symbiotic N2 fixing bacteria.

Answer:

  1. Acetobacter, Nitrococcus
  2. Rhizobium

Question 2.
Crop plants cannot grow well in the nitrogen-deficient soil while plants like Drosera and Nepenthes show vigorous growth.

  1. Justify the statement
  2. Mention any two deficiency shown by such crop plants.

Answer:
1. These plants are insectivorous plants. They capture and feed on insects in order to maintain the N2 content of their body.

2. Two deficiency shown by such crop plants

  • Stunted growth
  • Chlorosis

Question 3.
Study the relation of the given pair and fill up the blanks:

  1. Potassium: Stomatal movement:………… Constituent of chlorophyll
  2. ………………: pollen germination Zinc: biosynthesis of auxin.
  3. Ion exchange: Passive absorption ………….: Active absorption
  4. Protoplasmic streaming theory: De Vries: ………….Active absorption

Answer:

  1. Mg
  2. Boron
  3. Carrier concept
  4. Munch

Question 4.
Plants can be grown in defined nutrient solution in the absence of soil.

  1. Name the technique.
  2. Who demonstrated the technique for the first time?

Answer:

  1. Hydroponics
  2. Julius von sachs

Question 5.
How is nitrogenase enzyme protected?
Answer:
In leguminous plants, the enzyme nitrogenase is protected from Oxygen by the pigment leghaemoglobin.

Question 6.
The functional roles of certain essential elements are given below. Identify the element based on the function.

  1. Essential for the formation of Chlorophyll.
  2. Involved in the pollen germination.

Answer:

  1. Mg
  2. Boron

Question 7.
Explain the scientific reason for growing legume crops prior to cereal crops.
Answer:
Increase the fertility of the soil. Biological N2 fixation.

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 8.
Name the pink coloured pigment present in the root nodules? Write its role in N2 fixation?
Answer:
Leghemoglobin is an oxygen scavenger. It creates anaerobic condition for the action of nitrogenase enzyme to fix N2.

Question 9.
Give example for the following taking part in biological nitrogen fixation.

  1. Free-living N2 fixing bacteria
  2. Free-living N2 fixing cyanobacteria
  3. Symbiotic N2 fixing bacteria.
  4. Symbiotic N2 fixing cyanobacteria

Answer:

  1. Azotobacter, Clostridium
  2. Nostoc, Anabaena, Oscillatonia.
  3. Rhizobium leguminosarum
  4. Nostoc, Anabaena

Question 10.
Prepare a flow chart which shows the conversion of N2 to ammonia in biological N2 fixation.
Answer:
Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img2

Question 11.
A pigment similar to hemoglobin is present in leguminous plants. Name the pigment and write its role.

OR

How is nitrogenase enzyme protected?
Answer:
Leghemoglobin which is the scavenger of 02. Nitrogenase enzyme needs oxygen-free condition.

Question 12.
Observe the figure given below and answer the following questions.
Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img3

  1. Name this technique.
  2. Write two uses of this technique.

Answer:

  1. Hydroponics
  2. uses
    • Used as kitchen garden,
    • Used to study jdeficiency symptoms.

Question 13.
For the normal growth of plants it requires minerals. Write two examples of micro and macro elements.
Answer:

  • Macro – N, P
  • Micro-Boron, copper

Question 14.
In a survey done in an agricultural area the crops in the area shows various symptoms.

  • Chlorosis
  • Necrosis
  • Delay flowering.

Name the elements whose deficiency causes these symptoms.
Answer:

  • N, P, K, Mg
  • Chlorosis – N, K, Mg, S, Fe, Mn, etc.
  • Necrosis – K, Mg, Ca and Cu Delay flowering – N, S, and Mo

Question 15.
Iron is not a structural component of chlorophyll but its deficiency causes yellowing of leaves. Give reason.
Answer:
Iron activates catalise enzyme in the formation of chlorophyll.

Question 16.
Amides are derivatives of amino acids in which the hydroxyl group is replaced by the amino group (NH2)
a) How are asparagine and glutamine formed.
b) Amides contain more than amino acids.
Answer:
Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img4

Question 17.
In a survey done in an agricultural area the crops in the area shows various symptoms.

  • Chlorosis
  • Necrosis
  • Delay flowering

Name the elements whose deficiency causes these symptoms.
Answer:

  • N, P, K, Mg
  • Chlorosis – N, K, Mg, S, Fe, Mn, etc.
  • Necrosis – K, Mg, Ca and Cu
  • Delay flowering – N, S, and Mo

Question 18.
A farmer supplies Nitrogen fertilizer to pea plants.

  1. Is there any necessity to supply Nitrogen fertilizer?
  2. Justify your answer with reason.

Answer:

  1. No
  2. Symbiotic N2 fixation

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 19.
Name the respecive mineral nutrient element that

  1. Forms the core constituent of the ring structure of chlorophyll
  2. Activates carboxylases
  3. Forms the components of nitrogenase
  4. Synthesises middle lamella of plant cell.

Answer:

  1. Magnesium
  2. Manganese
  3. Molybdenum and iron
  4. Calcium

Question 20.
Observe the relationship between the first pair and fill in the blanks.
Posassium: Opening and closing of stomata::
Boron: …………
Answer:
Boron: Pollen germination/ pollen tube growth

Question 21.
State whether True or False.

  1. Potassium plays an important role in opening and closing of stomata.
  2. The movement of ions is usually called flux.
  3. In an LHC (Light-Harvesting complex), Chlorophyll b is the reaction center.
  4. The first stable product in calvin cycle is 3-PGA.

Answer:

  1. True
  2. True
  3. False
  4. True

Question 22.
A few inorganic elements are given. Match them with their specific functions.

Elements Function
1. Potassium a. Absorption and translocation
2. Magnesium b. Pollen germination
3. Molybdenum c. Opening and closing of Stomata
4. Boron d. Maintain ribosome structure

Answer:

Elements Function
1. Potassium Opening and closing of stomata
2. Magnesium Maintain ribosome structure
3. Molybdenum Absorption and translocation
4. Boron Pollen germination

Question 23.
Pick the suitable minerals from the list, for following processes?

  1. Synthesis of auxin
  2. Pollen germination
  3. Photolysis of water
  4. Nitrogen metabolism

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img5
Answer:

  1. Zn
  2. B
  3. Mn
  4. Mo

Question 24.
Rhizobium leguminosarum cannot do N2 fixation outside root nodules. Give reasons.
Answer:
Rhizobium can fix atmospheric N2 only if the symbiotic relationship with leguminose plant is established.

Question 25.
What type of conditions are created by leghaemoglobin in the root nodule of a legume?
Answer:
It acts as 02 scavenger that means it helps in preventing the combining of 02 with nitrogenase.

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 26.
Leguminous plants can be cultivated in between rice cultivation. Why?
Answer:
Because it increases the fertility of soil (enrich N2 content) for next year rice cultivation.

Question 27.
Match the element with its associated functions/ roles.

A. Boron i. Splitting of H2O to liberate o2 during photosynthesis
B. Manganese ii. needed for the synthesis of auxins
C. Molybdenum iii. component of nitrogenase
D. Zinc iv. Pollen germination
E. Iron v component of ferredoxin

Answer:

  1. A – iv
  2. B – i
  3. C – iii
  4. D – ii
  5. E – v

Question 28.
To get maximum yeild a farmer added exess amount of manganese-containing fertiliser. The plants showed some deficiency symptoms. Can you give the reason for this?
Answer:
Excess of the micronutrient -Mn causes Toxicity because it prevent the uptake of Iron, Magnesium, and calcium. This results in deficiency symptom.

Question 29.
Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img6

  1. Identify the phenomenon?
  2. A pink coloured protein protects nitrogenase from oxygen. Name that protein.

Answer:

  1. Ammonification
  2. Leghemoglobin

Question 30.

A B
Magnesium Opening and closing of stomata
Calcium Splitting of water
Potassium Middle lamella
Chlorine Chlorophyll

Answer:

A B
Magnesium Chlorophyll
Calcium Middle lamella
Potassium Opening and closing of stomata
Chlorine Splitting of water

Question 31.

  1. Name the oxygen-binding pigment found in the root nodule of plants like pea and bean.
  2. What is the normal colour of this pigment?

Answer:

  1. Leghemoglobin
  2. Pink-colored

Question 32.
How the presence of magnesium fulfills the requirements of the essentiality of elements from growth and development of plants?
Answer:

  1. It is a constituent of chlorophyll molecule and is essential for photosynthesis.
  2. It cannot be replaced by any other element for the same function.
  3. It is also required as a co-factor by many enzymes involved in cellular respiration and other metabolic pathways.

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 33.
Nitrogen fixation is shown by prokaryotes and not eukaryotes. Comment?
Answer:
In prokaryotes, photosynthetic autotrophs (cyanobacteria) like nostoc and Anabaena have special N2 fixing cell which helps in N2 fixation.

Question 34.
How is sulphur important for plants? Name the amino acids in which it is present.
Answer:
Sulphur, besides being present in some amino acids essential for protein synthesis, is also a constituent of several coenzymes, vitamins, and ferrodoxin which are involved in some biochemical pathways.

Question 35.
How do some bacteria carry out nitrification? What are such bacteria called?
Answer:
Such types of bacteria convert ammonia into nitrates and obtain energy for their activities. They are called chemosynthetic autotrophs.

Question 36.
Name the respective mineral nutrient elements of plants that:

  1. Is needed in the synthesis of auxins
  2. Is a constituent of ferredoxin
  3. Forms the core constituent of the ring structure of chlorophyll
  4. forms the components of nitrogenase and nitrate reductase

Answer:

  1. Zinc
  2. Sulphur
  3. Magnesium
  4. Molybdenum

Question 37.
Why do plants of legume family contain more protein than the other plants?
Answer:
Plants in legume family bears root nodules which bear symbiotic nitrogen-fixing bacteria i.e rhizobium

Question 38.
Nepenthes carries out photosynthesis and still traps insects. Why?
Answer:
Nepenthes grow in nitrogen-deficient soils so these trap, digest and absorb amino acids from the insects supplementing their nitrogen supply.

Question 39.
Mycorrohiza is a mutualistic association. How do the organisms involved in this association gain from each other?
Answer:
It is an association of root and fungi in which surface area of root is increased and more minerals can be absorbed. Fungus get nutrients and sugar from the plant.

Question 40.
Carnivorous plants like Nepenthes and Venus flytrap have nutritional adaptations. Which nutrient do they especially obtain and from where?
Answer:
In these, insect body is digested and plant gets Nitrogen as nutrients.

Question 41.
How are organisms like Pseudomonas and Thiobacillus of significance in nitrogen cycle?
Answer:
Pseudomonas and Thiobacillus carry out denitrification process wherein the nitrate present in the soil is reduced to nitrogen thus contributing to the atmospheric nitrogen.

Question 42.
Think of a plant which lacks chlorophyll. From where will it obtain nutrition? Give an example of such a type of plant.
Answer:
This case is observed in total parasites. In such plants they absorb food, water, and minerals from host. Eg cuscuta.

Question 43.
Nitrogen is essential element for plants and is found in abundance as atmospheric nitrogen. But most plants unable to use it. Why is it so and in what form do plants utilize them?
Answer:
Most plants cannot use it because atmospheric nitrogen is inert in its nature. Nitrogen fixers in soil can convert nitrogen gas into nitrates or nitrite or ammonium forms. These compounds enter the plants as nutrients through the roots and are assimilated as organic nitrogen.

Question 44.
How insectivorous plants fulfill their nitrogen requirements?
Answer:
Insectivorous plants fulfill their nitrogen requirements from insects and small animals trapped by their leaves(a pitcher).

Question 45.
All elements that are present in a plant need not be essential to its survival. Give reasons.
Answer:
The Criteria for essentiality are

  1. The element must be necessary for supporting normal growth and reproduction
  2. In the absence of elements, the plants do not complete their life cycle or set the seeds.
  3. The element must be directly involved in the metabolism of the plant.
  4. The requirement of the element must be specific and not replaceable by another.

Question 46.
Why is that in certain plants deficiency symptoms appear first in younger parts of the plant while in others they do so in mature organs?
Answer:

  • If the elements are actively mobilized, the older part of plant show deficiency symptoms.
  • If they are not mobilized, the deficiency symptoms are first observed in younger regions.

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 47.
Mineral elements are re-exported from one place to other or some are immobile and deficiency symptoms observed

  1. Which is the part of the plant show deficiency symptoms in the former?
  2. Name the mineral element is immobile and which part of the plant shows deficiency symptoms?

Answer:

  1. Older regions because minerals are remobilised from older regions into younger regions.
  2. Ca, Deficiency symptoms are noticed in younger tissues because it forms the structural part.

Plus One Botany Mineral Nutrition Three Mark Questions and Answers

Question 1.
Give the technical term for the following.

  1. Leaf yellowing
  2. death of tissues
  3. soilless cultivation

Answer:

  1. chlorosis
  2. Necrosis
  3. Hydroponics

Question 2.
Plants pick up nitrogen from the soil in the form of ammonia ions or nitrate ions, ammonia being the main product of biological nitrogen fixation. From the above view answer the following.
a) Which soil bacteria convert ammonia to NO2 – and NO3.
b) Draw a schematic diagram of progressive reduction of one molecule of nitrogen in the presentee of enzyme nitrogenase to yield two molecule of ammonia.
c) Name the enzyme for nitrogen assimilation in plants.
Answer:
Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img7

Question 3.
Macro and micronutrients are required in particular amount for plants.

  1. What will be the moderate increase of micronutrient affect the plants
  2. Name the micronutrient helps in pollen germination
  3. What is the concentration of macro and micronutrients required for plants?

Answer:

  1. It cause toxicity to plants and affect the uptake and utilisation of macronutrients
  2. Boron
  3. Macronutrients – Excess 10 millimole /kilogram of dry matter
    Micronutrients – Less than 10 millimole /kilogram of dry matter

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 4.
During formation of nitrate in plants, different steps occur.

  1. Name the steps leading to the conversion of atmospheric nitrogen to nitrate
  2. Which is the reductive and oxidative steps?
  3. Name the pigments and Enzymes that are required and the steps they act on.

Answer:

  1. Nitrogen fixation, Nitrification
  2. Nitrogen fixation—reductive process, Nitrification—Oxidative process
  3. pigment—Leghaemoglobin, Enzyme— Nirogenase Pigments and enzymes acts on Nitrogen fixation step

Question 5.
Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition img8

  1. Name the process
  2. Which enzyme catalyses the process
  3. How the enzyme in the process is protected from oxygen in root nodules?

Answer:

  1. N2 fixation
  2. Nitrogenase
  3. Due to the presence of pigment Leghemoglobin. It acts as the scavenger of oxygen.

Plus One Botany Mineral Nutrition NCERT Mark Questions and Answers

Question 1.
‘All elements that are present in a plant need not be essential to its survival’. Comment.
Answer:
The criteria for essentially of an element are given below:

1. The element must be absolutely necessary for supporting normal growth and reproduction. In the absence of the element, the plants do not complete their life cycle or set the seeds.

2. The requirement of the element must be specific and not replaceable by another element. In other words, deficiency of any one element cannot be met by supplying some other element.

3. The element must be directly involved in the metabolism of the plant. All elements that are present in a plant do not fulfill these criteria hence cannot be essential for plant survival.

Question 2.
Why is purification of water and nutrient salts so important in studies involving mineral nutrition using hydroponics?
Answer:
In 1860, Julius von Sachs, a prominent German botanist, demonstrated, for the first time, that plants could be grown to maturity in a defined nutrient solution in complete absence of soil. The essence of all these methods involves the culture of plants in a soil-free, defined mineral solution. These methods require purified water and mineral nutrient salts.

Purification of water and nurtient salt is important to rule out other influencing factors. The presence of pure nutrients will give clearcut scientific results. This will help in making a sound basis for the right prediction.

Question 3.
What are the steps involved in the formation of a root nodule?
Answer:
Steps in the development of root nodules:
1. Rhizobium bacteria contact a susceptible root hair, divide near it.

2. Upon successful infection of the root hair cause it to curl

3. Infected thread carries the bacteria to the inner cortex. The bacteria get modified into rod-shaped bacteriods and cause inner cortical and pericycle cells to divide. Division and growth of cortical and pericycle cells lead to nodule formation.

4. A mature nodule is complete with vascular tissues continuous with those of the root.

Plus One Botany Mineral Nutrition Multiple Choice Questions and Answers

Question 1.
1. Farmers in a particular region were concerned that premature yellowing of leaves of a pulse crop might cause a decrease in the yield. Which treatment could be most beneficial to obtain maximum seed yield?
(a) Frequent irrigation of the crop
(b) Treatment of the plants with cytokinins along with a small dose of nitrogenous fertilizer
(c) Removal of all yellow leaves and spraying the remaining green leaves with 2, 4, 5- thchlorophenoxy acetic acid
(d) Application of iron and magnesium to promote synthesis of chlorophyll
Answer:
(d) Application of iron and magnesium to promote synthesis of chlorophyll

Question 2.
For nitrogen fixation, useful pigment is
(a) nitrogenase
(b) hemoglobin
(c) myoglobin
(d) leghaemoglobin
Answer:
(d) leghaemoglobin

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 3.
Plants cultivated in nutrient solution without soil is called
(a) somatic hybridization
(b) tissue culture
(c) hydroponics
(d) suspension culture
Answer:
(c) hydroponics

Question 4.
The process of decay of dead organic matter is known as
(a) denitrification
(b) nitrification
(c) nitrogen fixation
(d) ammonification
Answer:
(d) ammonification

Question 5.
Zn, Mo, Fe, Cu are
(a) trace elements
(b) non-essentials
(c) macronutrients
(d) both a and b
Answer:
(a) trace elements

Question 6.
An essential element is that which
(a) improves health of the plant
(b) is irreplaceable and indispensable for the growth of plants
(c) is found in plant ash
(d) is available in the soil
Answer:
(b) is irreplaceable and indispensable for the growth of plants

Question 7.
N2 +8e +8H +16ATP → 2NH3+2H+ + 16ADP + 8e The above equation refers to
(a) amnionification
(b) nitrification
(c) nitrogen fixation
(d) denitrification
Answer:
(c) nitrogen fixation

Question 8.
Micronutrients are
(a) as important as macronutrients but are required in small amount
(b) less important than macronutrients
(c) called micro as they play only a minor role in plant nutrition
(d) required greater than 10m mole/Kg of dry matter
Answer:
(a) as important as macronutrients but are required in small amount

Question 9.
Which element is located at the centre of the porphyrin ring in chlorophyll?
(a) Potassium
(b) Manganese
(c) Calcium
(d) Magnesium
Answer:
(d) Magnesium

Question 10.
Which element is required for the germination of pollen grains?
(a) Boron
(b) Calcium
(c) Chlorine
(d) Potassium
Answer:
(a) Boron

Question 11.
Select the correct statement.
(a) Legumes are incapable of fixing nitrogen
(b) Legumes fix nitrogen through bacteria living fruits
(c) Legumes fix nitrogen only by bacteria present in root nodules
(d) frankia forms symbiotic association with algae
Answer:
(c) Legumes fix nitrogen only by bacteria present in root nodules

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 12.
Chlorosis is caused due to deficiency of
(a) magnesium
(b) calcium
(c) boron
(d) manganese
Answer:
(a) magnesium

Question 13.
Enzyme nitrogenase is responsible for
(a) nitrification
(b) nitrogen fixation
(c) nitrite reduction
(d) nitrate reduction
Answer:
(b) nitrogen fixation

Question 14.
Maximum percentage of which element occurs in plant ash?
(a) Magnesium
(b) Zinc
(c) Potassium
(d) Calcium
Answer:
(d) Calcium

Question 15.
Which of the following metals causes bone cancer
(a) Lead
(b) Cobalt
(c) Uranium
(d) strontium90
Answer:
(d) strontium90

Question 16.
Premature leaf fall is due to deficiency of
(a) phosphorus
(b) nitrogen
(c) calcium
(d) potassium
Answer:
(a) phosphorus

Question 17.
The function of leg haemoglobin during biological nitrogen fixation in root nodules of legumes is to
(a) convert atmospheric nitrogen to ammonia
(b) convert ammonia to nitrite
(c) transport oxygen for activity of nitrogenase
(d) protect nitrogenase from oxygen
Answer:
(d) protect nitrogenase from oxygen

Plus One Botany Chapter Wise Questions and Answers Chapter 8 Mineral Nutrition

Question 18.
Which of the following gene is responsible for biological nitrogen fixation?
(a) Nitrogenase
(b) N if gene
(c) Yeast alanine tRNA synthetase
(d) RNA synthetase
Answer:
(b) N if gene