Which of the following is free living nitrogen fixing cyanobacteria?

(1) Anabaena

(2) Azotobacter

(3) Beijernickia

(4) Rhodospirillum

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen metabolism |
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NEET 2022 - Target Batch - Aryan Raj Singh
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Rhizobium

(1) Rod shaped

(2) Legume-bacteria relationship

(3) Has relationship with roots of several legumes such as alfalfa, sweet clover sweet pea, Lentils, garden Pea, broad bean and clover beans

(4) All of these

Subtopic:  Nitrogen Fixation |
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NEET 2022 - Target Batch - Aryan Raj Singh
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The most common association on roots is as

(1) Lichens

(2) Nodules

(3) Beads

(4) Pneumathodes

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen metabolism |
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NEET 2022 - Target Batch - Aryan Raj Singh
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NEET 2022 - Target Batch - Aryan Raj Singh

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Rhizobium and Frankia

(1) Free living in soil

(2) Act as symbiont and fix nitrogen

(3) One is found on the roots of non-leguminous plants

(4) All of these

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen metabolism |
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NEET 2022 - Target Batch - Aryan Raj Singh
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The central portion of nodule is pink in color due to

(1) Leg- haemoglobin

(2) Haemoglobin

(3) RBC

(4) Myoglobin

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen metabolism |
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NEET 2022 - Target Batch - Aryan Raj Singh
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NEET 2022 - Target Batch - Aryan Raj Singh

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These are the events of Nodule formation:
a. Rhizobia get attached to epidermal and root hair.
b. Rhizobia multiply and colonise the surroundings of roots
c. Bacteria invade the root hair
d. The root hairs curl
e. An infection thread is produced
f. Bacteria are released from the thread into the cells
g. Infection thread carries the bacteria into the cortex of the root
h. The release of bacteria into cortex leads to the differentiation of specialised nitrogen fixing cells
i. Establishment of a direct vascular connection with the host for exchange
j. Nodule is formed finally
k. Initiation of nodule formation in the cortex of the root
Arrange them in order.
1. b-a-d-c-e-g-f-k-i-h-j
2. b-a-c-d-g-e-f-k-h-j-i
3. b-a-d-c-e-g-k-f-h-j-i
4. a-b-c-d-e-g-k-f-j-i-h

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen metabolism |
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NEET 2022 - Target Batch - Aryan Raj Singh
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NEET 2022 - Target Batch - Aryan Raj Singh

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Which of the following does not happen during nodule formation?

(1) Rhizobium bacteria contact a susceptible root hair, divide near it

(2) Successful infection of root hair causes it to curl

(3) Infected thread carries the bacteria to the inner cortex

(4) The bacteria get modified into rod shaped bacteroides and cause inner cortical and endodermal cells to divide

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen metabolism |
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Nodule formation is a result of

(1) Division and growth of cortical cells

(2) Division and growth of pericycle cells

(3) Division and growth of endodermal cells

(4) Both A and B

Subtopic:  Nitrogen Fixation |
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To produce two molecules of ammonia, how many ATP are hydrolysed?

(1) 16

(2) 8

(3) 4

(4) 32

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen metabolism |
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NEET 2022 - Target Batch - Aryan Raj Singh
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Enzyme Nitrogenase is

(1) Highly sensitive to the molecular oxygen

(2) Least sensitive to the molecular oxygen

(3) Highly sensitive to carbon dioxide

(4) Least active enzyme

Subtopic:  Nitrogen Fixation | Nitrogen Metabolism: 1 | Nitrogen Metabolism:2 | Nitrogen metabolism | Nitrogen Metabolism |
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NEET 2022 - Target Batch - Aryan Raj Singh
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

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