Problem 6 - Objective Biology for NEET

Question

Apical meristem is present at (a) Root and shoot apex (b) Place between mature tissue (c) Vascular cambium (d) Cork cambium

Step-by-Step Solution

Answer

The correct answer is (a) Root and shoot apex.

Step 1: Understand the Concept of Apical Meristem

The first step in solving this exercise is understanding what the apical meristem is. The apical meristem is a type of meristem, or growth tissue, in plants. It is found at the tips of roots and shoots and is responsible for the primary growth of the plant, which includes everything that extends outwards from the plant’s initial seedling stage.

Step 2: Eliminate Incorrect Answer Choices

After understanding the basic concept of the apical meristem, it's time to eliminate the incorrect options based on this understanding. Option (b) is incorrect because the apical meristem is not located between mature tissue. Similarly, options (c) and (d) are both incorrect because the apical meristem is not present at the vascular cambium or the cork cambium.

Step 3: Select the Correct Answer

Finally, after eliminating the incorrect options, the correct choice is clear. Option (a) is correct because the apical meristem is present at the root and shoot apex, in accordance with the basic concept and definition of the apical meristem.

Key Concepts

Root and Shoot Apex

Plants exhibit a remarkable feature where they continuously grow throughout their life. This attribute is primarily due to the apical meristem located at the root and shoot apex of a plant. In simpler terms, the tips of the plant’s roots and shoots house a special region where cells are in a constant state of division, leading to elongation.

The root apex is hidden underneath the soil and actively pushes downward, allowing the plant to access water and nutrients critical for survival. On the other hand, the shoot apex is responsible for the upward growth, contributing to the plant's ability to capture sunlight and carbon dioxide for photosynthesis. These regions are rich in undifferentiated cells, sometimes referred to as stem cells in the plant kingdom, because of their potential to transform into various types of plant cells.

Plant Primary Growth

The primary growth of plants refers to the elongation of the plant body that results in an increase in height and depth. This type of growth predominantly occurs in the apical meristems at the root and shoot tips. It's important to understand that primary growth enables young plants to establish themselves and compete for sunlight and nutrients.

The phenomenon of primary growth is not just about extension; it includes differentiation, where cells not only divide but also mature into specific cell types with defined roles, forming tissues such as xylem and phloem. This growth is directional, guiding the plant upward and roots further into the soil, supporting the plant's integration with its environment.

Meristem Tissue

Meristem tissue in plants is akin to a factory where cellular division is ongoing, producing new cells for growth and development. It’s a region of indeterminate growth, meaning these cells don’t have predestined functions upon their initial formation. They are pluripotent, meaning they hold the capacity to differentiate into a variety of cell types.

These tissues are classified based on their location and function. The most commonly known meristems are the apical meristems, which drive primary growth. Another category includes lateral meristems, such as vascular cambium and cork cambium, responsible for secondary growth or the increase in girth. However, it’s crucial to note that the exercise specifically points towards the apical meristem, associated with the initial and vertical growth of a plant, distinguishing it from other types.