Question

Continued growth due to activity of meristem is which type of growth? (a) Closed growth (b) Open growth (c) Both (a) and (b) (d) None of these

Short answer

The type of growth due to the continuous activity of meristem is Open Growth (option b).

Step-by-step solution

Understanding the Meristem

Meristem is the tissue in most of the plants containing undifferentiated cells (meristematic cells), which have the capability of division and contributing to plant growth.

Classifying Growth Type

There are mainly two types of growth - Open and Closed. Open growth is where plants grow throughout their life due to the presence of meristem at the tips of roots and shoots. Closed growth is where growth stops after reaching maturity, it's commonly seen in animals.

Relating with the stated question

The growth described in the question is 'continued growth due to activity of meristem'. On analyzing, this type of growth where meristem continues to divide and proliferate fits the definition of open growth.

Key concepts

Meristem Function

Understanding the functional role of meristem is crucial to grasping how plants grow and develop. Meristem tissues are akin to the stem cells found in animals; they are undifferentiated cells capable of division. The meristem is responsible for plant growth, and these cells divide continuously in a process that allows plants to grow taller and wider. In essence, these cells are the plant’s engine for growth and regeneration.

Meristematic cells are located in various parts of plants, such as the apical meristems at the shoot and root tips promoting length, and the lateral meristems, promoting girth in stems and roots through secondary growth. This growth process allows plants to add new leaves, flowers, and branches, and to increase their root system, thus enabling them to absorb more water and nutrients from the soil.

Open vs Closed Growth

The concepts of open and closed growth are fundamental to understanding how different organisms grow and reach their final forms. In the context of plants, open growth refers to the capacity for continual growth throughout a plant’s life cycle. This is made possible by the active meristems that persist at the plant's extremities. The tips of roots and shoots in many plants are sites of relentless cell division, which translates into new tissues and extended structures of the plant.

In contrast, closed growth is a characteristic of organisms like animals, where growth is determinate; it ceases once maturity is reached. These differences in growth patterns underscore the distinct ways in which organisms have adapted to their environments. Plants have evolved to continue growing in response to varying conditions, whereas many animals reach a certain size and then stop growing.

Plant Development

Plant development encompasses the entire journey from a seed to a mature plant, and it is governed by a coordinated progression of growth and differentiation. Various stages include seed germination, vegetative growth, flowering, and fruiting. During vegetative growth, cells at the meristems divide and differentiate into various tissues, leading to the formation of stems, leaves, and roots.

Importantly, plant development is adaptable and responsive to environmental conditions. Factors such as light, temperature, and water availability can influence the rate and pattern of development. This flexibility is essential for survival, as plants are stationary and must adapt to their immediate surroundings. It's the versatile roles of the meristems, through open growth mechanisms, that underpin this adaptability and allow plants not just to grow, but to thrive in dynamic environments.