Question

Growth rings are formed by the activity of.

• A. Extrastelar cambium
• B. Intrastelar cambium
• C. Interstelar cambium
• D. Both B and C

Answer 1

Answer: (D)

Both B and C

In dicotyledonous stems, during the intra stelar secondary growth, intra fascicular cambium and inter fascicular cambium joins together and form into a ring of cambium called Vascular cambium. Due to the influence of seasons of the year, vascular cambium produces two types of secondary xylems, spring wood or early wood and autumn wood or late wood. These spring wood and autumn wood together form into a ring of wood or secondary xylem called Annual ring.

So, the correct option is 'Both B and C'.