Question

Coralloid roots of___ have symbiotic association with $N_2$ - fixing cyanobacteria.

• A. Pinus
• B. Cedrus
• C. Cycas
• D. Ginkgo

Answer 1

Answer: (C)

Cycas

Answer 2

The coralloid roots of Cycas are symbiotically associated with nitrogen fixing blue-green algae, Anabaena cycadae and Nostoc punctiforme. In the middle cortex of coralloid roots, a broad blue green zone occurs, which is known as algal zone. Coralloid roots are irregular, negatively geotropic, dichotomously branched coral like roots which do not possess root hair and root caps.