Problem 21 - Biology the Easy Way (E-Z Biology)

Question

The word meristem refers to (a) rapidly growing cells (c) cells specialized for reproduction (b) old cells (d) differentiated cells

Step-by-Step Solution

Answer

(a) rapidly growing cells

Step 1: Understanding the Term

The term 'meristem' refers to a specific type of plant tissue. It's important to understand that meristems are regions in plants where cells are capable of division and growth.

Step 2: Identifying Characteristics

Meristematic cells are characterized by their ability to divide rapidly. This rapid cell division allows plants to grow in height and girth, and to form new organs like leaves and flowers.

Step 3: Matching Options to Characteristics

Examine each option provided: (a) rapidly growing cells match with the characteristic of meristematic cells, as they undergo frequent division. Option (b) old cells, (c) reproduction cells, and (d) differentiated cells do not pertain specifically to meristem tissue.

Step 4: Selecting the Correct Option

Given that meristem involves rapid growth through cell division, option (a) 'rapidly growing cells' accurately describes meristem. The other options do not match the primary function or nature of meristematic cells.

Key Concepts

Plant Tissue

In plants, tissues play a crucial role in ensuring proper growth and functioning. Plant tissue refers to groups of cells that work together to perform specific tasks. Unlike animal tissues, plant tissues are more flexible and can adapt to various environmental conditions. Plant tissues are categorized into two main types:

• Meristematic Tissue: This is the tissue where all plant growth originates. It contains undifferentiated cells, known as meristematic cells, which are capable of division.
• Permanent Tissue: These are differentiated cells that no longer divide. They form from meristematic cells and perform specific functions such as photosynthesis and support.

Understanding these basic categories provides insight into how plants grow and maintain their structure.

Cell Division

Cell division is a fundamental process where a single cell divides to produce two new daughter cells. In plants, this process is crucial for growth and repair. The two primary types of cell division are:

• Mitosis: This is the process by which meristematic cells divide. It produces genetically identical cells, allowing the plant to grow in size and replace worn-out tissue.
• Meiosis: This type of division is involved in the reproduction of plants and results in the formation of gametes (sex cells).

In meristematic regions, mitosis is constantly happening, making these areas critical for the primary and secondary growth of the plant.

Plant Growth

Plant growth is a complex process involving cell division, elongation, and differentiation. It occurs predominantly in specific areas known as meristems. Growth can be divided into two phases:

• Primary Growth: This occurs at the tips of roots and shoots, allowing the plant to extend vertically. Meristems involved here are known as apical meristems.
• Secondary Growth: This increases the girth of the plant. It occurs in lateral meristems like the vascular cambium, which thickens the stems and roots.

Plant growth is a dynamic process driven by internal and external factors, including light, water, and nutrients.

Meristematic Cells

Meristematic cells are unique and vital for plant life. These cells are characterized by their small size, thin walls, and lack of vacuoles. They constantly divide and are responsible for growth. Key points to understand about meristematic cells include:

• Undifferentiated Nature: These cells have the ability to become any type of plant cell. This potential allows a plant to develop diverse tissues and organs.
• Location: Found in meristem regions, such as the roots, shoots, and branches, they are pivotal for plant growth.
• Role in Healing: Due to their regenerative ability, meristematic cells also help in repairing damaged tissues.

These cells are essential for both vertical and horizontal growth, making them the backbone of plant development.