NTA Abhyas NEET2020BotanyAnatomy of Flowering PlantsPractice
Annual rings are formed by the activity of
Options
- ACambium
- BSecondary xylem
- CPhellogen
- DXylem and phloem
Correct answer
A. Cambium
Step-by-step solution
During secondary growth, vascular cambium divides to form secondary xylem which forms wood. The activity of cambium varies in the spring and autumn season. For plants growing in the temperate region, more quantity of light coloured wood is formed in the spring season and less quantity of dark coloured wood is formed in the autumn season. These concentric light and dark coloured wood constitutes an annual ring.