Tag: apical dominance

Questions Related to apical dominance

Substances which originate at the tip of stem and control growth elsewhere are

  1. Enzymes

  2. Hormones

  3. Vitamins

  4. None of the above


Correct Option: B
Explanation:

A chemical substance produced in one part of body and regulates the activity of other parts is called as hormones. Plant hormones are produced in the stem, bud and root tips and control the plant growth, formation of flowers, stems, leaves, development, and ripening of fruit, etc. Auxins are specialized hormones which acts on the tip.

Thus, the correct answer is option B.

Apical dominance means

  1. Suppression of growth of apical bud by axillary buds

  2. Suppression of growth of axillary buds by the presence of apical buds

  3. Stimulation of growth of axillary buds by removal of apical buds

  4. Inhibition of growth of axillary buds by removal of apical buds


Correct Option: B
Explanation:

Auxins are generally produced by the growing apices of the stems and roots, from where they migrate to the regions of their action. In most higher plants, the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called as apical dominance. 

Apical dominance is thought to be due to production of auxins in the stem tips. Removal of shoot tips (decapitation) usually results in the growth of lateral buds. It is widely applied in tea plantations, hedge-making.