AP BIOLOGY

Detailed explanation-1: -The increase in length of the shoot and the root is referred to as primary growth. It is the result of cell division in the shoot apical meristem. Secondary growth is characterized by an increase in thickness or girth of the plant. It is caused by cell division in the lateral meristem.

Detailed explanation-2: -Apical meristem is responsible for increase in length of the plant.

Detailed explanation-3: -Primary growth results in the increase in length of the primary plant body. Primary growth occurs at the apical meristem (a meristem located at the tip of a stem). A meristem is a region of undifferentiated cells from which new cells arise through cellular division.

Detailed explanation-4: -Arising from lateral meristems, secondary growth increases the width of the plant root or stem, rather than its length. As long as the lateral meristems continue to produce new cells, the stem or root will continue to grow in diameter.