Question

Besides paddy fields, cyanobacteria are also found inside the vegetative part of?

• A. Cycas
• B. Psilotum
• C. Pinus
• D. Equisetum

Answer 1

The correct option is A

Cycas

The correct option is A.

Explanation of correct option:

1. Cyanobacteria (blue-green algae) are unicellular organisms that undergo photosynthesis.
2. Some cyanobacteria (e.g., Anabaena, Nostoc) help in nitrogen fixation. They are abundantly found in paddy fields.
3. Cycas is a gymnosperm that belongs to the Cycadaceae family. It contains a special type of root called ‘coralloid roots’.
4. Anabaena cycadeae are mostly found in the coralloid roots. They form a symbiotic relationship with Cycas plants.
5. Anabaena converts atmospheric nitrogen into ammonia which is utilized by the host plant. In return, the host plant provides a habitat for Anabaena.

Explanation of incorrect option:

Option B:

1. Psilotum are vascular plants that belong to the Psilotaceae family.
2. They lack true roots and contain rhizomes.

Option C:

1. Pinus are gymnosperms in which the ovules are not enclosed in the ovary wall.
2. The roots of Pinus form a symbiotic association with fungi and this is known as ‘mycorrhiza’.

Option D:

1. Equisetum are vascular plants that reproduce through seeds.
2. They possess adventitious roots that develop from the stem.

Final answer: Besides paddy fields, cyanobacteria are also found inside the vegetative part of Cycas.