Shoots and Stems PDF

Shoots and stems The shoot system is part of the plant that develops from the plumule after embryo in the seed. It usually grows above the ground and is made-up of a stem bearing branches, leaves but flowers and fruits There are two types of buds There is a vegetative bud which will develop into...

Shoots and stems The shoot system is part of the plant that develops from the plumule after embryo in the seed. It usually grows above the ground and is made-up of a stem bearing branches, leaves but flowers and fruits There are two types of buds There is a vegetative bud which will develop into a leaf branch or other vegetative path of the plant The other type of bud is a reproductive or flower bud that will develop into a flower or a group of flowers Typical stems A typical stem has leaves at regular intervals called nodes, buds at the axle of the leaf and a terminal border at the growing point. The length of the stem between the nodes is called the internode. The typical stem stands erect from the ground Functions of stems Our plan stem has the following functions Connects the root system to the leaves and flowers and the shoot system Supports all parts of the shoot system, including branches leaves buds, flowers and fruits Use the leaves to facilitate the absorption of the maximum amount of sunlight it's branches habit of growth Transports water and dissolved minerals and nutrients from the root to the leaves Transports food for example sugars made in the leaves to other parts of the plant where it is needed or stored Transport in the stem There's a network of tubes inside the plant that transports water food and other substances throughout the plant Figure 8.3 shows the internal tubes of the plant. The xylem consists of xylem Vessels and is responsible for carrying water from the roots through the stem and through the veins in the leaves. The phloem is made of sieve tubes and is responsible for carrying food made in the leaves to other parts of the plant. The xylem and phloem phone in structures called vascular bundles Modified stems Not all stems look the same for example, you can see Runners - horizontal stems such as pumpkins and cucumbers Rhizomes - horizontal underground stem such as ginger and turmeric bulbs - shortened underground stems such as in onions vines- long thin stems in climbing plants such as red kidney beans Besides the main functions, stems can also be used by the plant in the following waves Storage of food - sometimes the centre of the stem is used as a food storage area for example in sugar cane Perennation - The stem helps the plant to survive from one year to the next inner dormant state. Examples of plants that use modified underground stems in this way I I root underground stems have been modified to form bulbs, corna or rhizomes.\ -