Question

Which of the following forms the branch of the tree?
A. Axillary stem
B. Crown
C. Apical Stem
D. None of the above

Answer 1

Hint: Crown in plants is referred to the foliage and branches of the trees growing outward from their trunk. Apical dominance occurs because the shoot apical meristem produces auxin, a plant hormone which prevents axillary buds from growing.

Complete answer:
The apical bud grows to give rise to the central stem and the axillary stem is responsible for forming the vegetative or reproductive branch of the tree.

Hence, the correct option is option A i.e. Axillary stem.

Additional information: An axillary bud is also known as embryonic shoot which remains dormant at the junction of the stem and the petiole of a plant. It arises exogenously from the outer layer of the cortex of the stem. Whereas axillary stem left behind during the elongation of stem capable of giving rise to different plant parts.
Subaerial modifications of Stem are:-
In the subaerial modifications, the stem remains partly aerial and partly they will be underground. Some short aerial branches and the adventitious roots develop at the nodes. Detachment of the entire branch or a node can form into a new plant. Such plants are commonly called creepers and their subaerial stem modifications are meant for vegetative propagation.
1. Runner:- A creeping stem having long internodes, which runs horizontally on the soil surface. Runner arises from the axillary bud. Runners break off and further grow into individual plants. Examples – grass, Oxalis.
2. Sucker:- Arises from the underground part of the main stem. It further grows horizontally for about a small distance under the soil and then emerges straight upwards. It forms a leafy shoot and adventitious roots before separating from the parent plant. The common sucker- banana, Mint, etc.
3. Stolon:- Grows aerially and bends downward towards the ground. Eg- strawberry.
4. Offset:- Found in aquatic plants like eichornia.

Note:
Apical meristem is a type of meristematic tissue which is present at the tip of the roots, branches and the stems. They are mainly responsible for axial growth in a plant. Growth is associated with these meristems.