stems transport nutrients and water between leaves and roots. They hold up the leaves towards sunlight. They also produce leaves and roots.

see explanation for solution

The **dicot stem** have a well-structured epidermis with a cuticle. Its internal structure is mainly composed of epidermis, hypodermis, cortex endodermis, pericycle, and vascular bundle. The vascular bundle in this stem is arranged in a ring-like formation

The **monocot stem** looks circular in shape with the hollow axial parts which give rise to nodules, internodes, leaves, and branches of the plant. The size of stems differs in different plant species. It has sclerenchyma cells bundled on the outside of the vascular tissue bundle. It does not have any trichomes and the vascular bundle is scattered all throughout the stem.

The **primary growth** of the plant happens at the **apices or tips of the stems** and **roots**. It is the result of rapidly dividing cells present in the shoot tips and root tips.

**Secondary growth** refers to the growth that results from the cell division in the cells present in the lateral meristems, which includes the vascular and cork cambium of the plant.

Hence, the correct answer is **primary growth**

Primary growth

**Heartwood** is the inner layer of the tree that is made up of old xylems that no longer function. **Sapwood** surrounds the heartwood and transports water and nutrients. The heartwood is of a darker color than the sapwood.

The stem is the main part of the plants transport system, because it facilitates the transfer of water and nutrients throughout the plant. The subsystems of the transport process are xylems and phloems. These are the vascular tissues that links the different parts of the plant together, enabling the transfer of nutrients.

A tuber is a modified stem that enables a plant to store food for a later use. In a potato plant, tubers grow at the end of the underground stems. They act as storage organs for food and nutrients that will help them to regrow for the next season or to survive any unfavorable condition that may happen.