Question

Assertion : Endomycorrhiza of forest trees contribute to the efficient nutrient cycling in tropical forest ecosystems.

Reason : The fungi that form endomycorrhizal associations with plants store nutrient ions and make them available to the host plants.

(a) Both A and R are true and R is the correct explanation of A  

(b) Both A and R are true but R is not correct explanation of A  

(c) A is true but R is false  

(d) A and R are false

Answer 1

Correct option (a) 

Explanation :

The fungi of endotrophic mycorrhiza invade the cells of the root cortex, with a portion lying externally as a loose mass of hyphae in the soil. These mycorrhizas are found in the families of Ericales, Orchidaceae and Gentiaceae. Mycorrhizas cause considerable stimulation to growth in nutrient deficient soils. The greatest stimulation occurs in the uptake of phosphates. Mycorrhizas can take up phosphate at that low concentrations at which they are unavailable to non-mycorrhizal roots.