Question

What is the significance of coralloid
roots in cycas in biology class 11​

Answer 1

Answer:

It is negatively genotypic roots that contain nitrogen fixation bacteria like cyanobacterium. They are found in cycad plants. It is important as it supply nitrogen to the bacteria which is required for the growth and development of the plant.

Answer 2

Answer:

Coralloid roots help in nitrogen fixation as well as respiration due to lenticels.

Explanation:

• There exist two types of roots in Cycas. Taproot is positively geotropic, non-green and devoid of root hairs. Mainly helps in anchorage and water and mineral absorption.

• These highly modified coralloid roots are lateral branches of the taproot. First, it grows horizontally i.e. diageotropic and then, repeatedly divide dichotomously, comes out of the soil surface in the form of coral-like mass. These lack root hairs and root caps.

• The anatomy reveals that the middle cortex carries Blue-green algae (BGA) such as Anabaena and Nostoc symbiotically.

• These coralloid roots help in nitrogen fixation which contributes to the nutrient need of the plant as well as respiration through the lenticels.