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CBSE Questions for Class 11 Medical Biology Mineral Nutrition Quiz 9 - MCQExams.com
CBSE
Class 11 Medical Biology
Mineral Nutrition
Quiz 9
Which one is essential for nitrogen fixation?
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0%
Copper
0%
Zinc
0%
Manganese
0%
Molybdenum
Explanation
Nitrogen fixation is the process of conversion of atmospheric nitrogen into salts of nitrogen which can be easily used by the plants. It takes place in presence of an enzyme known as nitrogenase enzyme. It is produced by certain cyanobacteria and helps in the reduction of nitrogen to ammonia. It is made up of two component dinitrogenase and dinitrogenase reductase. The dinitrogenase contains a cofactor of iron and molybdenum which helps in reduction of nitrogen to ammonia.
So, the correct answer is option D.
Deficiency symptons of nitrogen and potassium are visible first in.
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0%
Young leaves
0%
Roots
0%
Buds
0%
Senescent leaves
Match the identidy the correct option.
I
II
(a)
Zn
(i)
Bronzing in legume
(b)
Cl
(ii)
Mottled leaf in Citrus
(c)
Ni
(iii)
Whiptail in Cauliflower
(d)
Mo
(iv)
Mouse ear in pecan/ hickory
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a-ii, b-i, c-iv, d-iii
0%
a-iv, b-i, c-iii, d-ii
0%
a-ii, b-iii, c-iv, d-i
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a-i, b-ii, c-iii, d-iv
Which of the following gene is responsible for biological nitrogen-fixation?
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0%
Nitrogenase
0%
Nif gene
0%
RNA synthetase
0%
Yeast alanine tRNA synthetase
Explanation
Nif genes are the nitrogen-fixing gene which encodes for proteins that are involved in nitrogen fixation. Nitrogenase complex is the primary enzyme which is encoded by nif genes. It also encodes the regulatory protein involved in the nitrogen fixation. It is found in both free-living and symbiotic nitrogen fixers. The gene is inserted to plant which are deficient by the technique of nif gene cloning.
So, the correct answer is option B.
There is no direct transfer of electron from cyt b to cyt c as
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0%
Energy is not available
0%
The two are not nearby
0%
Electrons are transported in pairs
0%
Electrons have no affinity for cytochromes
Minerals that activate respiratory enzymes
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0%
N and P
0%
Mg and Mn
0%
K and Ca
0%
S and Fe
0%
Cu and Bo
Every mineral element that is present in a cell is needed by the cell .
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0%
True
0%
False
Explanation
Most of minerals element present in a cell but all of these may not be essential for their survival. For example, in the growing plant near the radioactive site deposited (bioaccumulate) radioactive metals in the plants, similarly, gold and selenium deposited in the growing plant near mining sites, However, it does not mean these elements are essential for the plant.
So, the correct answer is option B.
In plants, micronutrients are those which are needed less than or equal to the ................ amount per gram of dry matter.
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0.1 mg
0%
0.1 g
0%
$$0.1 \mu g$$
0%
$$1.0 \mu g$$
Explanation
Micronutrients or microelements are that elements which required in the small amount to the plants, in traces it is about 0.1 mg or less than o.1 mg of dry matter.
Cobalt, aluminium, Fe and nickel may be essential certain plants but required in the small amount.
So, the correct answer is option A.
Oil yielding legume is
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0%
Carthamus
0%
Glycine max
0%
Ricinus
0%
Vigna sinensis
Explanation
Soybean is commonly known as Glycine max. It belongs to the family of legumes. It provides the fermented products like milk, tofu etc. Oil of Glycine max is rich in linoleic and oleic components. It is used for many industrial purposes, e.g., in the manufacture of soaps, glycerine, linolenic, etc. It has a nitrogen-fixing ability and helps in the enrichment of soil with nitrogen.
So, the correct answer is option B.
If all the microorganisms are destroyed on earth then
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The earth will be covered by dead bodies
0%
We cannot produce antibodies
0%
All life form will become immortal
0%
Soil will be depleted from nitrogen
Explanation
Microorganism plays an important role in the enrichment of soil. The dead and decaying matter in the soil is decomposed by the microorganism in the soil. Nitrogen-fixing microorganism breaks the complex compounds like proteins into amino acids and finally to nitrogen and increases the fertility of the soil. If all the microorganism are destroyed on earth then the soil will be depleted from nitrogen.
So, the correct answer is option D.
Root nodules for nitrogen fixation of a non-leguminous tree possess
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0%
Frankia
0%
Rhizobium
0%
Azotobacter
0%
Thiobacillus
Explanation
Frankia
forms root nodules of non-leguminous plants like actinorhizal plants.
Rhizobium
forms a symbiotic relationship with leguminous plants.
Azotobacter
is free-living nitrogen-fixing bacteria.
Thiobacillus
is not associated with nitrogen fixation.
So, the correct answer is 'Frankia'
A legume having a symbiotic association with both of the nitrogen-fixing bacteria
Rhizobium
and
Azorhizobium
is?
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0%
Crotalaria juncea
0%
Sesbania aculeata
0%
Sesbania rostrata
0%
Cyamopsis tetragonoloba
Explanation
Sesbania rostrata
is a small semi-aquatic leguminous tree, in the genus
Sesbania
. It forms a symbiotic relationship with Gram-negative
Rhizobia
and
Azorhizobium
which leads to the formation of nitrogen-fixing nodules on both stem and roots.
So the correct answer is
'Sesbania rostrata'
Leguminous plants are able to fix atmospheric nitrogen through symbiotic activity. Which is not correct?
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Leghaemoglobin scavenges oxygen and is pinkish in colour.
0%
Nitrogenase is insensitive to oxygen.
0%
Nodules act as sites for nitrogen fixation.
0%
The enzyme nitrogenase catalyses the conversion of atmospheric nitrogen to ammonia.
Which one is a symbiotic nitrogen fixing plant?
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0%
Pinus
0%
Azolla
0%
Marchantia
0%
Moss
The chemical fertilizer required for better rhizobial nitrogen fixation is ______.
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0%
Phosphorus
0%
Potassium
0%
Calcium
0%
Sodium
Explanation
Nitrogen fixation is a process of conversion of atmospheric nitrogen into its compounds. The process of nitrogen fixation requires a reducing power, energy source (ATP), dinitrogenase enzyme, and compound for trapping $$NH_3$$. Phosphorous increased the nitrogen-fixing capacity of legumes plants, stimulates the root production, helps in the transformation of sugar, energy transfer, etc.
Hence, the correct answer is option A, i.e., Phosphorus.
How does the nitrogen fixation occur in legumes?
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By specialized bacteria in their roots
0%
By specialized bacteria in their leaves
0%
Independent of bacteria that live in them
0%
Not by any of the above methods
Explanation
Nitrogen fixation is the conversion of atmospheric nitrogen into nitrates and ammonia by nitrogen-fixing bacteria which are associated with the roots of the legume plants.
Examples of nitrogen fixing bacteria includes
Rhizobium
So, the correct answer is 'By specialized bacteria in their roots'
Nitrogen fixation is the conversion of
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Nitrogen $$\rightarrow$$ Ammonia
0%
Nitrogen $$\rightarrow$$ Nitrates
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Nitrogen $$\rightarrow$$ Amino acids
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Both A and B
Explanation
Nitrogen fixation is conversion of atmospheric nitrogen into nitrates and ammonia by nitrogen fixing bacteria.
So, the correct answer is both A and B.
Azotobacter
and
Bacillus polymyxa
are
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Decomposers
0%
Non-symbiotic nitrogen fixers
0%
Symbiotic nitrogen fixers
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Pathogenic bacteria
Explanation
Azotobacter
and
Bacillus polymyxa
are non-symbiotic nitrogen fixers.
Rhizobium
is an example for symbiotic nitrogen fixer.
Staphylococcus aureus, Sreptococcus pyogenes
are pathogenic bacteria.
Fungi are classical examples of decomposers.
So, the correct answer is 'Non-symbiotic nitrogen fixers'
Which of the following is correct?
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Legumes fix nitrogen through bacteria in their leaves.
0%
Legumes fix nitrogen through bacteria in their roots.
0%
Legumes fix nitrogen independent of bacteria.
0%
Legumes do not fix nitrogen.
Explanation
Nitrogen fixation is accomplished with the help of nitrogen-fixing microbes, mainly
Rhizobium.
The enzyme nitrogenase plays an important role in biological nitrogen fixation and is very sensitive to oxygen. Nodule formation involves a sequence of multiple interactions between
Rhizobium
and roots of host plant.
So, the correct answer is 'legumes fix nitrogen through bacteria in their roots'
Which of the following is not considered as the criterion for essentiality?
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The element must be directly involved in the metabolism of plant.
0%
The element must be absolutely necessary for supporting normal growth and reproduction.
0%
The requirement of the element may be specific and not replaceable by another element.
0%
In the absence of the element, the plant does not complete a specific function.
Example of an ammonifying bacteria is
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0%
Clostridium
0%
Azotobacter
0%
Nitrosococcus
0%
Bacillus ramosus
Explanation
Ammonifying microorganisms example are
1) Bacillus ramosus
2) B.vulgaris
3) Clostridium
4) Actinomycetes etc
So the correct option is "Bacillus ramosus".
Which of the following does not possess
Rhizobium
containing nodules?
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0%
Pisum
0%
Cicer
0%
Phaseolus
0%
Pinus
Explanation
Since above all options belong to the leguminous family and pinus is the sole genus in the subfamily Pinoideae.
So the correct option is "Pinus".
When we boil tulsi leaves in water, water acquires a characteristic smell of leaves because
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0%
Smell of leaves diffuse in water
0%
Leaves melt in water
0%
Stored wastes in the leaves dissolve in water
0%
Leaves pollute water
Explanation
Tulsi is a traditional herb that is used in India since ancient times. It is used as an immunity booster by making various types of decoctions. The decoction involves boiling tulsi leaves in water. When tulsi leaves are boiled in water phytochemicals diffuse into the water resulting in the characteristic smell.
Thus the correct answer is option A.
Nitrogen fixation is
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Nitrogen $$\rightarrow$$ Ammonia
0%
Nitrogen $$\rightarrow$$ Nitrates
0%
Nitrogen $$\rightarrow$$ Amino acid
0%
Both A and B
Explanation
Correct option: D
Explanation:
Nitrogen fixation
is the conversion of nitrogen present in the air to nitrogenous compounds in the soil.
They are either converted by the
nitrifying bacteria
or the
nitrogen-fixing bacteria
present in association with plant roots.
Nitrogen fixation help
increase the fertility
of the soil.
Nitrogen is converted to both
ammonia and nitrates
in the soil.
Hence, n
itrogen fixation is "
b
oth A and B
".
Find out the odd one in nitrogen cycle
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0%
Pseudomonas
0%
Clostridium
0%
Nostoc
0%
Rhizobium
Explanation
Reduction of nitrates to nitrogen gas is called denitrification.
Pseudomonas
is a denitrifying bacteria. Denitrification is the process that converts nitrate to nitrogen gas, thus removing bioavailable nitrogen and returning it to the atmosphere.
While
Clostridium, Nostoc, Rhizobium
are all nitrogen-fixing bacteria that convert free nitrogen into forms used by plants.
So the correct option is "
Pseudomonas
".
An association which fixes nitrogen through non-nodulation is
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0%
Maize roots with
Spirillium notatum
0%
Digitaria roots with
Spirillium notatium
0%
Coralloid roots of Cycas with
Anabaena
0%
All the above
Explanation
Cycas has coralloid roots in association with Anabaena or Nostoc. Cycas form a symbiotic nitrogen-fixing association but without nodule formation.
So the correct option is "Coralloid roots of Cycas with Anabaena".
What is the role of
pseudomonas
in nitrogen cycle?
Report Question
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Fixes elemental nitrogen
0%
Produces elemental nitrogen
0%
Transfers nitrogen
0%
Changes ammonium nitrogen to nitrate state
Explanation
The transformation of nitrates to nitrogen gas or nitrous oxide by certain microorganisms is called denitrification. Pseudomonas is a denitrifying bacteria.
So the correct option is "produces elemental nitrogen".
Old leguminous roots turn green due to
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0%
Conversion of leghaemoglobin to chl a
0%
Breakdown of leghaemoglobin
0%
Conversion of leghaemoglobin to chl b
0%
Conversion of leghaemoglobin to chl c
Explanation
Because old legume plant is not able to synthesize leg-hemoglobin properly or we can say that there is a breakdown of leg-hemoglobin(pink colored protein) So the old legume plant turns green.
So the correct option is "breakdown of leghaemoglobin".
.
Which is wrongly matched?
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Rhizobium
- Free living nitrogen fixer
0%
Humus - Abiotic component
0%
Phosphorous cycle - Sedimentary
0%
Cedrus deodara
- Coniferous forest
0%
Shorea robusta
- Tropical deciduous forest
Explanation
Rhizobium live as aerobes under the free-living conditions (where nitrogenase is not optional), but during nitrogen-fixing events, they become anaerobic(thus protecting the nitrogenase enzyme).
So the correct option is "Rhizobium-free living nitrogen fixer".".
Which one of the following bacteria reduces nitrate to gaseous nitrogen?
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0%
Azospirillum
0%
Nitrosomonas
0%
Nitrococcus
0%
Pseudomonas
Explanation
The reduction of nitrate back to the environment as nitrogen, i.e., denitrification. This process done by
Pseudomonas, Clostridium
bacteria in their life cycle.
So. the correct answer is option D.
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