Problem 4 - Objective Biology for NEET

Question

Depending on whether the cells being formed are capable of dividing or not, the plant tissues are classified into how many types? (a) 1 (b) 2 (c) 3 (d) 4

Step-by-Step Solution

Answer

The correct answer is (b) 2 types.

Step 1: Retrieving Knowledge on Plant Tissue Classification

On the basis of whether or not the cells being formed have the capability to divide, plant tissues are generally classified into two categories. These are meristematic tissues (capable of dividing) and permanent tissues (incapable of dividing after maturity).

Key Concepts

Meristematic Tissues

Meristematic tissues are the vital growth regions of plants and are characterized by their ability to undergo active cell division. These tissues are responsible for plant growth, primarily in length and girth. They are found in specific areas of the plant, such as the tips of roots and shoots, known as apical meristems. Other types may include lateral and intercalary meristems.
Some key characteristics of meristematic tissues include:

• Small, densely packed cells with thin cell walls.
• Large nuclei and very little vacuole space.
• Cells are in close contact with one another.
• High metabolic activity due to continuous cell division.

These tissues are crucial for plant development, enabling the plant to grow taller, generate new leaves, and form branches.
Understanding meristematic tissue is fundamental in grasping how plants sustain growth and adapt to their environments.

Permanent Tissues

Permanent tissues arise from meristematic cells that have completed their division and have taken on specific roles within the plant. These cells mature to develop structures that perform vital functions, with several types formed to meet the plant's needs.
Permanent tissues can be further categorized into simple and complex tissues.

• Simple Permanent Tissues: Composed of a single cell type, these include parenchyma, collenchyma, and sclerenchyma. Each plays a distinct role, such as storage in parenchyma or support in sclerenchyma.
• Complex Permanent Tissues: Made from more than one type of cell, such as xylem and phloem, responsible for water and nutrient transport.

These tissues provide structural support, aid in storage and photosynthesis, and ensure efficient resource distribution throughout the plant.
By comprehending permanent tissues, one gains insight into how plants sustain functions essential for survival and reproduction.

Cell Division in Plants

Cell division is a fundamental process that allows plants to grow, reproduce, and repair damaged parts. In plants, this process predominantly occurs in the meristematic tissues, where cells are continuously dividing.
Two main types of cell division processes take place in plants:

• Mitosis: This form of cell division results in two daughter cells that are identical to the parent, essential for tissue growth and maintenance.
• Meiosis: Although less frequent, meiosis occurs in reproductive cells and leads to genetic variation, forming gametes (sperm and eggs).

The cycle of cell division involves several phases:

• Prophase, where chromosomes condense and spindle fibers form.
• Metaphase, the alignment of chromosomes in the center.
• Anaphase, where chromatids separate and move to poles.
• Telophase, where nuclear membranes reform and the cytoplasm divides.

Understanding cell division in plants is key to knowing how they grow, develop, and produce offspring. By observing this process, one can better appreciate the resilience and adaptability of plant life.