Question

What kind of growth involves roots and shoots but not reproductive structures and occurs in most plants?

Answer 1

Growth in roots and shoots of most of the plants is of 2 types: primary growth and secondary growth.

Explanation:

Growth in roots and shoots of most of the plants occurs in two ways, i.e. increase in length, termed linear growth and increase in girth or diameter of the organ.

The linear growth that increases the length of root and shoot is termed primary growth . It occurs in all seed bearing plants and also in non-seed bearing plants, like mosses and ferns. Primary growth involves addition of new cells due to the activity of meristematic cells (primary meristem) in shoot apex and root apex in shoot and root, respectively. Cell division is followed by cell elongation and differentiation.

Monocots in Angiosperms have only primary growth. Gymnosperms and dicots in Angiosperms have secondary growth in root and stem, involving increase in girth or diameter of the organ, following primary growth. Secondary growth occurs due to the activity of vascular cambium and cork cambium or phellogen. These meristems are lateral meristems , adding cells in the lateral direction. Vascular cambium is partially primary meristem and partially secondary meristem. Cork cambium is a secondary meristem.