Question

Q.7.The formation of annual
ring is due to variation
in the activity of cambium.:
O A. Temperature
O B. Seasonal
O C. Rainfall
O D. Altitude​

Answer 1

Answer:

B. Seasonal

Explanation:

In dicotyledonous stems, during intra stelar secondary growth, intra fascicular cambium(primary meristem) and inter fascicular cambium(secondary meristem) joins together and form into a ring of cambium is called vascular cambium.

It is partly primary meristem and partly secondary meristem.

Its activity is continuous and uninterrupted. Due to the seasonal influence, it produces two types of secondary xylems, spring wood and autumn wood. Both these woods, together form into a ring of wood called annual ring or growth ring. Every  

annual ring becomes sap wood and every sap wood gradually transform into heart wood. Due to these transformations amount of heart wood increases.

so, the correct option is 'Activity of vascular cambium due to seasonal variations'.

Answer 2

Answer:

The formation of annual Ring is due to variation of differential seasonal activity of cambium