DENDROLOGY

Detailed explanation-1: -Auxin is involved in cell growth and cell expansion, so it is produced primarily in parts of the plant that are actively growing like the stem (specifically, the very tiptop of the stem).

Detailed explanation-2: -Auxins are a powerful growth hormone produced naturally by plants. They are found in shoot and root tips and promote cell division, stem and root growth.

Detailed explanation-3: -Auxin is a key regulator of plant growth and development, orchestrating cell division, elongation and differentiation, embryonic development, root and stem tropisms, apical dominance, and transition to flowering.

Detailed explanation-4: -In roots, a high concentration of auxin inhibits cell elongation, slowing growth on the lower side of the root, while cells develop normally on the upper side and causing the root to bend toward the high concentration of auxin and thus causing the root to grown down.