Have you ever wondered why various flowers are different in their looks, place of origin and season of growth? Why don’t you find your favourite marigold flowers in the scorching summers? Well, there is a lot of story behind it! In this chapter, we will discuss everything about roots. Ever thought that roots are that significant? Yes! Before, we proceed, we will have a quick recap of what morphology is all about
What is Morphology?
Morphology is the branch of science related to the study of form and structure of anything. In botany, it generally means the study of external features, forms and relative positions of different organs on plants. Angiosperms or flowering plants show a great variety of shape, size and form.
They could range from minute Wolffia and Lamna (0.1cm) to the tall Eucalyptus (up to 100 meters). Now we head on to read more about a significant part of the flowering plants: the roots.
The root is usually an underground part of the plant. It is primarily responsible for the fixation and absorption of water. The root with its branches is known as the root system. Now, we move ahead and look at the characteristics of the roots in various plants.
Characteristics of the Root
- The root is the descending portion of the plant axis.
- It is positively geotropic.
- It is usually non-green or brown in colour.
- The root is not further differentiated into nodes and internodes.
- As per the rule, the root does not bear leaves and tree buds.
- Usually, a root cap protects the root tip.
- The root bears unicellular root hairs.
- Lateral roots arise from the root. These are endogenous in origin (arises from pericycle).
Without the roots, the transportation system in many plants would cease to exist. Therefore, it is important that you understand the need for roots. However, there are more than one types of root systems in plants. We will now look at them in brief.
Types of Root System
The root system is generally of two types. We will look at these two types in the section below.
- Taproot system: The taproot system develops from radicle of the germinating seed. It is also called the normal root system. The taproot system is present in only dicotyledonous plants.
- Adventitious root system: The root system that develops from any part of the plant body other than the radicle is called the adventitious root system. It is mostly seen in monocotyledonous plants.
Regions of the Root
- Root Cap: The root cap is a thimble-like structure covering the tip of the root. The root cap protects the tender root apex when it makes its way through the soil.
- Region of Elongation: This part is responsible for the meristematic activity. The cells in this region are very small, have a thin wall and dense protoplasm.
- Region of Maturation: We get the root hairs in this region. These are a part of the root epidermis.
Modifications of Root
- Food storage: Taproots of turnip and carrot are examples where roots are modified for food storage.
- Support: In banyan trees, hanging roots come out from branches. The hanging roots then go into the soil to provide additional support to the huge banyan tree.
- Respiration: In swampy plants, many roots come out vertically above the ground. These are hollow roots and their primary function is the exchange of gases in the roots.
Solved Examples for You
Question: Pneumatophores or breathing roots occur in
- Mangrove plants
Solution: Pneumatophores are respiratory roots belonging to Mangrove plants. Hence, the correct answer is option d.
Question: Haustoria or sucking roots occur in
Solution: The parasitic plant produces some knob like roots at the point of attachment with the host plant known as haustoria which penetrate into the host plant and draws nourishment. Therefore, the correct answer is option c.