Question

Meristematic cells are characterized by (a) thin cellulosic cell walls (b) dense protoplasm (c) prominent nuclei (d) all of these.

Short answer

Meristematic cells are characterized by all of the listed features: thin cellulosic cell walls, dense protoplasm, and prominent nuclei.

Step-by-step solution

Understanding Meristematic Cells

Meristematic cells are undifferentiated or partially differentiated cells in plants that have the capability to divide and give rise to various specialized cell types. They are found in zones of the plant where growth can take place.

Analyzing the Characteristics

To answer the question, one must know the characteristics of meristematic cells. These cells typically have thin cellulosic cell walls to facilitate cell division, dense protoplasm due to the abundance of cellular activities, and prominent nuclei since they actively control cell division and differentiation.

Selecting the Correct Option

Given the characteristics provided, we can understand that all options (a), (b), and (c) are true for meristematic cells. Therefore, the correct answer includes all these features.

Key concepts

Cell Division in Plants

Meristematic cells play a pivotal role in plant growth because they are the engines behind cell division in plants. Understanding cell division is crucial for comprehending how plants grow and regenerate. In plants, the most common form of cell division is called mitosis, during which a single cell divides to produce two identical daughter cells, each with the same number of chromosomes as the parent cell.

During cell division, the plant's genetic material is duplicated, and the cell's organelles are distributed between the two new cells. This process ensures that each new cell receives all the components necessary for survival and function. It's essential for the continuous growth of plant tissues and organs, such as leaves, roots, and stems.

• Mitosis in meristematic cells is responsible for the growth in length (primary growth) and diameter (secondary growth) of the plant.
• Meristematic cells, due to their thin cellulosic walls, are more adaptable to the process of division, allowing the plant to grow quickly in response to its environment.
• The division of meristematic cells can also initiate the repair of damaged tissues or regenerate parts of the plant that have been lost.

Cell Differentiation

Cell differentiation is a critical process following cell division which leads to the development of various cell types with specialized functions. After meristematic cells divide, they often differentiate into specific types of cells that make up the distinct tissues within a plant.

During differentiation, cells undergo changes in size, shape, and metabolism, leading to an array of plant cells such as xylem, phloem, or epidermal cells. Each of these cells will have a unique role to play within the plant's overall structure and function. As such, differentiation is necessary for the plant to develop specialized systems like the vascular system for transporting water and nutrients.

• Cell differentiation is governed by both internal genetic factors and external environmental cues.
• This process is reversible in plants, allowing differentiated cells to return to a meristematic state if needed, a process known as dedifferentiation.
• Differentiated cells work together to perform complex functions that support the plant's life cycle, such as photosynthesis and reproduction.

Plant Growth and Development

The ultimate outcome of cell division and differentiation is plant growth and development. Growth in plants is not just an increase in size, but also an increase in number of cells, complexity, and specialization of tissues and organs. It is a methodical and dynamic process directed by genetic instructions and influenced by environmental conditions.

Plant development includes not only the formation of leaves, flowers, and roots but also the maturity of these structures to fulfill their designated functions. For instance, meristematic cells near the tips of roots and shoots enable the plant to extend its reach for sunlight and nutrients from the soil.

• Plant growth involves both cell division and cell expansion, with cells increasing in volume after division.
• Development includes not only morphological changes but also physiological and biochemical changes across the plant's lifecycle.
• Plants exhibit plasticity in their growth patterns, meaning they can adapt their form and structure in response to their environment.