Which statement best characterizes secondary growth? a. It results from cell divisions in the vascular and cork cambia. b. It increases the length of the plant stem. c. It results from divisions in the apical meristem cells. d. It often produces phloem cells to the inside and xylem cells to the outside of the vascular cambium.

Verified step by step guidance

1. Step 1: Understand the concept of secondary growth. Secondary growth in plants refers to the process that results in an increase in the thickness or girth of the plant. This is different from primary growth, which increases the length of the plant.
2. Step 2: Evaluate each statement in relation to the concept of secondary growth. Statement a suggests that secondary growth results from cell divisions in the vascular and cork cambia. This is true as these are the areas where secondary growth occurs.
3. Step 3: Statement b suggests that secondary growth increases the length of the plant stem. This is incorrect as it is primary growth, not secondary growth, that increases the length of the plant.
4. Step 4: Statement c suggests that secondary growth results from divisions in the apical meristem cells. This is incorrect as apical meristem cells are responsible for primary growth, not secondary growth.
5. Step 5: Statement d suggests that secondary growth often produces phloem cells to the inside and xylem cells to the outside of the vascular cambium. This is incorrect as secondary growth typically produces xylem cells to the inside and phloem cells to the outside of the vascular cambium. Therefore, the correct answer is a.