Parts of a Plant – Roots, Stems and Leaves

Learn all about the parts and functions of the main plants parts in this fun and informative video.

Structures that are observable on the outside of a plant are external structures. These include roots, stems, leaves, flowers and fruits.

Roots are usually the external structures that grow down into the soil. The primary function of the roots is to take in the water and nutrients the plant needs to survive and grow.

Some roots are shallow and branch out to cover a large area. These roots are called fibrous roots. Fibrous roots help the plant to take up lots of water when it rains. Growing out from the roots are microscopic root hairs. The root hairs help in absorbing water and nutrients from the soil.

Other plants have one main root, called a taproot, which grows deep into the soil. This helps to reach water deeper in the soil. Roots also hold plants firmly in place. This helps to prevent them from being washed away by water or blown away by wind.

Many plants have a stem. Stems can be different in many ways, but they usually perform two important functions for the plant.

Plants need the energy from sunlight in order to make food through the process of photosynthesis – a process that takes place in the leaves. One function of the stems in many plants is to hold up the plant. This allows the leaves to absorb more sunlight. Stems also hold up the plant’s reproductive structures – flowers and fruits.

Some plants have stems that are soft and can bend easily. They are called herbaceous plants. Herbaceous stems grow quickly. Other plants, such as trees, have stiff, strong stems. They are called woody plants. The strong stems of woody plants grow thicker and taller each year. This allows the plants to reach high into the sky where the leaves can trap the sunlight they need to photosynthesize.

For protection against animals, some plants have coverings on their stems. Trees have an outer layer of bark. Some plants like roses and bougainvilleas have stems with thorns for protection against animals.

Plants are organisms that absorb the energy in sunlight to make food through the process of photosynthesis. In most plants, photosynthesis takes place in the leaves. To take in lots of sunlight, leaves are external structures that are often flat and branch out to cover a large area.

The key to making food is what lies inside the leaf. We’ll take a look at that in more detail later.

Leaves have a large surface area for absorbing sunlight, but this can also lead to water loss. To reduce water loss, many leaves have a waxy outer covering called a cuticle.

Some plants in hot and dry environments like deserts store water in their leaves. They have a thick cuticle to prevent water loss.

The bryophyllum plant can reproduce from its leaves. Small plantlets with roots develop along the edges of the leaves. The plantlets can grow into new plants when they fall to the ground.

The leaves of the plant are where the food-making process of photosynthesis takes place. In order to photosynthesize, the external and internal structures in the leaves work together as a system. Let’s take a closer look!

Water and nutrients travel in the xylem from the roots through the stem to the cells in the leaves. Tiny holes, mostly on the underside of the leaves, called stomata, open and close to take in the air the plant needs.

Inside the cells of a leaf are special structures called chloroplasts. Chloroplasts are the part of the cell where photosynthesis takes place. In chloroplasts, the energy from sunlight is used to convert carbon dioxide and water into food for the plant. The food is transported from the leaves to the rest of the plant in phloem tubes.