Question

Plants having little or no secondary growth are

• A. grasses
• B. deciduous angiosperms
• C. conifers
• D. cycads

Answer 1

The correct option is A grasses

Increase in the height of the plant is known as the primary growth. Increase in girth of the plants is known as the secondary growth. Lateral meristem or cambium is responsible for this growth. The secondary growth is absent in monocots. Secondary growth involves the activity of cork cambium and vascular cambium. Cambium is absent in between the xylem and phloem in monocots and hence, there is no secondary growth in monocots such as grasses. Such a vascular bundle is known as a closed vascular bundle.

In gymnosperms, such as conifers and cycads, and dicots such as deciduous angiosperms, cambium is present in between xylem and phloem. Such a vascular bundle is known as an open vascular bundle and it is responsible for secondary growth.