Mineral Nutrition In Plants Question 35
Question: Assertion : Nitrogen-fixing bacteria in legume root nodules survive in oxygen-depleted cells of nodules. Reason : Leghaemoglobin completely removes oxygen from the nodule cells. [AIIMS 2004]
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: D
Solution:
Rhizobium species (e.g., Leguminosarum, R.lupini etc) live in symbiotic association in the root nodules of leguminous plants like, pea, gram etc.
In the soil the bacteria cannot fix nitrogen.
After entering the legume root, the bacterium induces cell membrane.
A pink-red pigment called leghaenoglobin lines the membrane and the protects the bacteriods from the oxygen.
BETA
