Question

Q1) ASSERTION: leguminous plants are nitrogen fixers. REASON: leguminous plants have Rhizobium in their root nodules. *
1)Both assertion(A) and reason(R) are true and reason (R) is correct explanation of assertion(A)
2)Both assertion (A)and reason(R) are true but reason(R) is not correct explanation of assertion(A)
3)Assertion (A) is true but reason (R) is false
4)Assertion(A)is false but reason(R)is true

2. ASSERTION: Use of manure greatly enhances crop productivity. REASON: watering plants is very important in increasing crop productivity *
Both assertion(A) and reason(R) are true and reason (R) is correct explanation of assertion(A)
Both assertion (A)and reason(R) are true but reason(R) is not correct explanation of assertion(A)
Assertion (A) is true but reason (R) is false
Assertion(A)is false but reason(R)is true
13. ASSERTION: Tooth decay causes due to the action of acids.REASON: Bacteria breakdown the sugars present from the left over food and release acids. *
Both assertion(A) and reason(R) are true and reason (R) is correct explanation of assertion(A)
Both assertion (A)and reason(R) are true but reason(R) is not correct explanation of assertion(A)
Assertion (A) is true but reason (R) is false
Assertion(A)is false but reason(R)is true
14. ASSERTION: villi are present in small intestine.REASON: complete digestion takes place in large intestine *
Both assertion(A) and reason(R) are true and reason (R) is correct explanation of assertion(A)
Both assertion (A)and reason(R) are true but reason(R) is not correct explanation of assertion(A)
Assertion (A) is true but reason (R) is false
Assertion(A)is false but reason(R)is true
15. ASSERTION: Wool fibres are plant fibres.REASON: The under fur of kashmiri goat is soft and used to make Pashmina shawls.
Both assertion(A) and reason(R) are true and reason (R) is correct explanation of assertion(A)
Both assertion (A)and reason(R) are true but reason(R) is not correct explanation of assertion(A)
Assertion (A) is true but reason (R) is false
Assertion(A)is false but reason(R)is true

Answer 1

Answer:

There are two types of nitrogen-fixing bacteria one is free-living bacteria like cyanobacteria (Nostoc) and another one is symbiotic bacteria like Rhizobium. Rhizobium forms a symbiotic association with the roots nodules of leguminous plants for nitrogen fixation. Thus, the correct answer is option A.