Question

Intrinsic heterophylly is found in all except (a) Cotton (b) Buttercup (c) Coriander (d) Larkspur.

Short answer

Cotton (option a) is the plant that does not exhibit intrinsic heterophylly.

Step-by-step solution

Understanding Intrinsic Heterophylly

Intrinsic heterophylly refers to the occurrence of different types of leaves on the same plant at different stages of development or in different environmental conditions. This phenomenon is observed in certain plant species that have evolved this as an adaptive feature.

Identifying Plants with Intrinsic Heterophylly

Among the options given, buttercup, coriander, and larkspur are known to exhibit intrinsic heterophylly. They have variations in leaf shape at different stages of their growth or in response to changes in their environment.

Eliminating Plants with Intrinsic Heterophylly

Since we are looking for a plant that does not exhibit intrinsic heterophylly, and we have identified buttercup, coriander, and larkspur as having this characteristic, we can eliminate these options leaving us with cotton.

Key concepts

Plant Adaptation

Plants have developed a remarkable ability to adapt to their environment, which is essential for survival. This practice, known as plant adaptation, involves various strategies, including modifications in structure, composition, and physiology. Intrinsic heterophylly is a shining example of such an adaptation.

For instance, aquatic plants may develop floating leaves to maximize sunlight absorption, while desert plants often have thick, fleshy leaves to conserve water. In environments where predation pressure from herbivores is high, some plants may produce thorny or bitter-tasting leaves to deter consumers. These adaptive features reflect the plant's capability to modify traits in response to specific environmental challenges, ensuring their growth, reproduction, and survival.

Understanding the underlying reasons for these adaptations can reveal much about the ecosystems in which these plants thrive, as well as offer insights on how to promote biodiversity and conservation efforts. The array of forms and functions in plant adaptations is a testament to the diverse and dynamic nature of life on Earth.

Plant Development Stages

As plants grow from seeds to mature individuals, they pass through various plant development stages. These stages, ranging from germination, seedling growth, vegetative growth, flowering, pollination, seed formation, to senescence, reflect the plant's morphological and physiological changes over time.

During the early stages of development, plants form simple leaves that support initial growth, which might be quite different from the leaves seen in later stages. Intrinsic heterophylly connects closely with developmental changes, as certain plant species produce different types of leaves as they mature. This can be for a range of reasons, such as improving photosynthetic efficiency, adapting to new environmental conditions, or enhancing reproductive success.

Each development stage is crucial and prepares the plant for the subsequent stage. Understanding these stages aids in the identification of unique characteristics like intrinsic heterophylly and supports agricultural practices, ensuring optimal growth and yield.

Leaf Variation

The variety seen in plant leaves, commonly known as leaf variation, encompasses differences in shape, size, texture, and even color among leaves from the same plant or between different plants. These variations are often tightly linked to environmental adaptations and developmental changes.

In the context of intrinsic heterophylly, leaf variation is particularly interesting because it occurs on a single plant. This can be noticed in various lifecycle stages or as a response to environmental changes. Some leaves may be broad and flat to capture sunlight efficiently, whereas others might be narrow to minimize water loss. Some aquatic plants may have submerged leaves that are finely divided to survive underwater, and aerial floating leaves to interact with the air and sunlight above water.

This ability to diversify leaf form, even within a single organism, helps plants to maximize their resources and chances of survival. By observing and studying leaf variation, botanists and ecologists can infer a lot about the habitat preferences and even the evolutionary history of plant species.