HORTICULTURE

Detailed explanation-1: -The key to plant growth is meristem, a type of plant tissue consisting of undifferentiated cells that can continue to divide and differentiate. Meristem allows plant stems and roots to grow longer (primary growth) and wider (secondary growth).

Detailed explanation-2: -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.

Detailed explanation-3: -Meristems are the regions of cells that are capable of growth and undergo rapid cell division, which is when cells make more cells through a process known as mitosis. Apical meristems, which control the lengthening of roots and stems, are responsible for the majority of primary growth.

Detailed explanation-4: -Root growth is closely related to carbon import and hence to light conditions at the shoot. Carbon gain in roots is realized predominantly by import from the shoot via the phloem, while the major loss of root carbon occurs via respiration associated with growth and ion uptake.

Detailed explanation-5: -There are three phases of growth – meristematic, elongation and maturation.