Question

Apical dominance means
A. Suppression of growth of apical bud by axillary buds.
B. Suppression of growth of axillary buds by the presence of apical buds.
C. Stimulation of growth of axillary buds by removal of apical buds.
D. Inhibition of growth of axillary buds by removal of apical buds.

Answer 1

Hint: Apical dominance results due to the production of auxins in the stem tips. When we remove the tips of the shoots, it will result in the growth of lateral buds. This method is usually employed in tea plantations.

Complete step by step answer:
Apical dominance is the phenomenon in which the apical portions of the shoot will have control over the lateral buds outgrowths. The classical explanation for correlative inhibition has focused on the nutrient hypothesis. The remarkable progress that has been made in the technology of endogenous hormones quantification in plant tissue has not been accompanied by elucidating the mechanism of hormones action in the dominance of apical. In many studies, it has shown that the apical tissues are very rich in auxins which will indirectly suppress the growth of axillary buds which is supported by the cytokinin growth hormones which are originating from the shoots and the roots. The auxin-induced oligosaccharide signals originate from the cell walls of the shoot tips which may act as the secondary inhibitors to the bud growth. The auxin which is produced apically will suppress the lateral bud growth by not exporting the auxin to the buds. By understanding and manipulating the endogenous cytokinin and auxin ratios will be useful in plant tissue culture by modulating the hormones.
Hence, the correct answer is option B.

Note: Auxins are produced abundantly in the growing apices of the roots and stems; from there they migrate to the various regions for their actions. In higher plants the growing apical bud will prevent the growth of the lateral buds; this phenomenon is called apical dominance.