Which meristem tissue in stems promotes secondary growth, increasing girth?

Which meristem tissue in stems promotes secondary growth, increasing girth?

• A. Meristem
• B. Cambium
• C. Stomata
• D. Phloem

Answer: (B)

Secondary growth in stems comes from a lateral meristem called cambium. This tissue sits between the xylem (inside) and phloem (outside) and continually divides to add new layers: secondary xylem to the inside and secondary phloem to the outside. That production builds more vascular tissue and pushes the stem outward, increasing girth. Other options don’t fit because meristem is a general growth tissue and doesn’t specify where thickening happens; stomata are for gas exchange on the epidermis and aren’t involved in stem thickening; phloem is a transport tissue produced by cambium, not the growth site itself.

Secondary growth in stems comes from a lateral meristem called cambium. This tissue sits between the xylem (inside) and phloem (outside) and continually divides to add new layers: secondary xylem to the inside and secondary phloem to the outside. That production builds more vascular tissue and pushes the stem outward, increasing girth.

Other options don’t fit because meristem is a general growth tissue and doesn’t specify where thickening happens; stomata are for gas exchange on the epidermis and aren’t involved in stem thickening; phloem is a transport tissue produced by cambium, not the growth site itself.