Problem 76 - Objective Biology for NEET

Question

Diadelphous condition is found in (a) Citrus (b) Pea (c) China rose (d) Tomato

Step-by-Step Solution

Answer

The Diadelphous condition is found in Pea.

Step 1: Understanding Diadelphous condition

In the Diadelphous condition, the stamens of a flower are united in two separate bundles or groups by their filaments. It's a characteristic feature of several plant species.

Step 2: Recall and Match

Now recall which of the given plants (Citrus, Pea, China Rose, Tomato) has this Diadelphous condition.

Step 3: Selection

By remembering the characteristic feature of these plants, it's identified that Pea plant has the Diadelphous condition. In the Pea flower, 9 out of the 10 stamens have their filaments fused together and the remaining one is free.

Key Concepts

Stamens

Stamens are one of the essential parts of a flower, primarily responsible for reproduction. In most flowers, the stamen includes two main components:

• Filament: This is the slender thread-like stalk that supports the anther. It helps in positioning the anther for effective pollen release.
• Anther: This is the part that produces pollen, which is the male gamete in plants.

In the structure of a flower, stamens are usually situated around the pistil, which is the female part of the flower.
In the botanical world, the arrangement and fusion of stamens can vary significantly across different species. Certain plants exhibit particular stamen arrangements like the diadelphous condition, where stamens are grouped into bundles.
This unique arrangement has implications for the pollination and reproduction strategies of plants.

Flower structure

The structure of a flower is beautifully complex, comprising several parts, each serving a crucial role in the plant's reproductive process.

• Calyx: Usually consisting of green sepals, the calyx protects the flower in its bud stage.
• Corolla: These are the petals of the flower, often vibrant and colorful to attract pollinators.
• Stamens: Known as the male part of the flower, they produce pollen.
• Pistil: This is the female reproductive part of the flower, which includes the stigma, style, and ovary.

Each component of the flower works in harmony to ensure the process of fertilization occurs successfully.
In some flowers, like those of the pea plant, structural variations such as the diadelphous condition occur, affecting how the flower operates. This specific condition in pea plants creates two groups of stamens, impacting the way pollination happens.

Pea plant

The Pea plant, scientifically known as Pisum sativum, is a fascinating species, particularly noted for its unique flower structure that exhibits the diadelphous condition.
In peas, typically 9 out of the 10 stamens have their filaments fused, forming a bundle, while one remains free.
This specific arrangement is an adaptation that aids in the plant's reproduction process by facilitating efficient pollen transfer.

• The Pea plant has compound leaves with leaflets and tendrils for climbing.
• The flowers are usually white or purple, contributing to the plant's reproductive success by making them attractive to pollinators.
• It is a legume, playing a significant role in nitrogen fixation, enriching the soil with necessary nutrients.

The pea plant is not only educational in understanding plant structures and conditions like diadelphous but also significant in agriculture and environmental sustainability.