Give scientific reasons: When the apical bud is removed,the next axillary bud begins to grow out.

(N/A) $1$. The apical bud is the primary site of $Auxin$ synthesis in plants.
$2$. $Auxin$ produced in the apical bud moves downwards and suppresses the growth of lateral or axillary buds,a phenomenon known as $Apical$ $Dominance$.
$3$. When the apical bud is removed,the source of $Auxin$ is eliminated.
$4$. Due to the absence of $Auxin$,the inhibitory effect on the axillary buds is lifted,allowing them to grow out and develop into new branches.