Question

Apical dominance in plants means
A. Growth of lateral buds
B. Inhibition of growth of lateral buds
C. Both A and B
D. None of the above

Answer 1

Hint: Apical dominance is the phenomenon to inhibit growth of lateral buds. It helps in the growth of shoot apex. Apical bud is present at the end of shoot. Auxin is present at the shoot apex which inhibits the growth of lateral buds.

Complete step by step answer:
 Apical dominance occurs at the shoot apex. It inhibits the growth of lateral buds so that plant may grow vertically. It is defined as the control exerted by the terminal bud over the outgrowth of lateral buds. Stem of the plants shows phototropism while the roots of the plants show geotropism. Food is prepared in the leaves by using sunlight. Phyto-hormones plays very important role in growth and development of the plant. These hormones include auxin, cytokinins, gibberellins, abscisic acid and ethylene. Auxin is
the present at the end of the shoot tip contains an apical bud. The inhibition of growth of the lateral buds further down on the stem towards the axillary bud is due to the presence of auxins. In 1934, it was found that auxin regulates apical dominance. It is present in the growing shoot. From the above information we know that apical dominance in plants means inhibition of growth of lateral buds.

So, the correct answer is option B.

Note: Lateral buds start growing when the IAA concentration is lowered and produce new shoots. Apical dominance is used for hedge building, or artistic sculptures which are called topiary. Removal of SAM stimulates the growth in the lateral direction. Apical dominance is high in some of the fruit plants. If the limbs are broken by accident, apical dominance can be reduced. In “Ballerina” apple trees, strong apical dominance is observed.