Problem 70 - Objective Biology for NEET

Question

How many types of tissue systems are present in plant depending on their structure and function? (a) 1 (b) 2 (c) 3 (d) 4 ssue Susten

Step-by-Step Solution

Answer

There are 3 types of tissue systems present in a plant depending on their structure and function.

Step 1: Understand Basic Plant Tissue Classifications

In plants, tissues are divided into three types based on their structure and function: Dermal tissue system (which forms the outer covering of the plant), Vascular tissue system (which is responsible for the transportation of substances), and Ground tissue system (which carries out photosynthesis, stores materials, and helps in the regrowth of the plant).

Step 2: Match the Number of Identified Tissue Systems with Given Options

After the identification of the three basic tissue systems in plants, it is clear that the correct answer is the option that represents '3'.

Key Concepts

Dermal Tissue System

The dermal tissue system is like the skin of the plant. It forms the outer protective layer, shielding the plant from the external environment. This system consists primarily of the epidermis, which is a single layer of cells covering leaves, flowers, roots, and stems. These cells serve as a barrier against injury, water loss, and infection by pathogens.

• Epidermis: The outermost layer of the plant, responsible for protection.
• Stomata: Pores on the leaf surface that regulate gas exchange, essential for photosynthesis.
• Cuticle: A waxy layer that covers the epidermis, providing additional protection and helping to prevent water loss.
• Trichomes: Hair-like structures that can reduce water loss and offer protection against herbivory.

In some plants, the dermal tissue system also includes specialized modifications like root hairs, which improve water and nutrient absorption by increasing the surface area of roots.

Vascular Tissue System

The vascular tissue system is crucial for the transportation of water, nutrients, and sugars throughout the plant. Think of it as the plant's circulatory system. This system consists of two main types of tissues: xylem and phloem.

• Xylem: Responsible for transporting water and minerals from the roots to the rest of the plant. The xylem cells are tubular and reinforced with lignin, making them strong and supportive.
• Phloem: Transports organic nutrients, especially glucose, from the sites of photosynthesis (leaves) to other parts of the plant.

This system ensures that all parts of the plant receive the necessary resources to maintain growth, support, and functions essential to survival.

Ground Tissue System

The ground tissue system fills much of the interior of the plant, providing essential functions such as photosynthesis, storage, and support. This system is composed of three types of cells:

• Parenchyma: These cells are versatile and the most common. They participate in photosynthesis in leaves and store starch, oils, and water in roots and stems.
• Collenchyma: Responsible for providing flexible support to young parts of the plant without restricting growth.
• Sclerenchyma: These cells are thick-walled and serve a structural role, providing strength and support to areas no longer actively growing.

The ground tissue system not only helps the plant remain upright but also supports processes such as healing and regrowth, especially during injury or after being grazed by animals.