Problem 66 - Objective Biology for NEET

Question

Twisted aestivation is found in all except (a) Cotton (b) China rose (c) Lady's finger (d) Gulmohar

Step-by-Step Solution

Answer

The correct answer is (d) Gulmohar. Its flowers don't show twisted aestivation.

Step 1: Analyzing Option A - Cotton

Research or use existing botanical knowledge to determine the aestivation pattern of Cotton flowers. Cotton belongs to the Malvaceae family. This family generally shows twisted aestivation.

Step 2: Analyzing Option B - China Rose

Research or use existing botanical knowledge to determine the aestivation pattern of China Rose flowers. China Rose also known as Hibiscus or Rosa-sinensis also belong to the Malvaceae family and exhibits twisted aestivation.

Step 3: Analyzing Option C - Lady's finger

Research or use existing botanical knowledge to determine the aestivation pattern of Lady's Finger flowers. Lady's finger, scientifically known as Abelmoschus esculentus, belongs to the Malvaceae family as well. Its flower also follows the twisted aestivation pattern.

Step 4: Analyzing Option D - Gulmohar

Research or use existing botanical knowledge to determine the aestivation pattern of Gulmohar flowers. Gulmohar, known scientifically as Delonix regia, belongs to the Fabaceae family. Its flowers show valvate or imbricate aestivation, not twisted aestivation.

Key Concepts

Twisted Aestivation

Twisted aestivation is a unique arrangement of flower petals where each petal appears to slightly overlap its neighbor in only one direction, similar to how you might twist a paper windmill. Imagine holding a stack of papers and twisting them so that each sheet slightly covers the one below it. This type of overlapping is common among certain flowering plant families, including the Malvaceae family.

Importance of Twisted Aestivation

Understanding twisted aestivation is not just about recognizing patterns, it's crucial for botanists and horticulturists to classify plants and determine how they have evolved over time. This aestivation method can play a role in the biology of a flower, including how it attracts pollinators and protects its reproductive parts during development.

Malvaceae Family

The Malvaceae family, commonly known as the mallow family, is home to a variety of flowering plants that include both decorative and economically important species such as cotton, hibiscus, and okra (Lady's finger).

Members of this family typically share characteristics like having leaves with a palmate vein pattern, and as mentioned, flowers with twisted aestivation.

Diverse and Widespread

The Malvaceae plants are renowned for their adaptability and can be found in both tropical and temperate climates. They are essential not only because they add beauty to our gardens but also because they have practical uses; for example, cotton fibers are a staple of the textile industry, while okra is a nutrient-rich food source.

Flower Anatomy

Diving into flower anatomy gives us insight into the sophisticated structure and functions of a flower. It includes several parts such as the sepals, petals, stamens, and carpels.

The aesthetic and structural layout of these components, including their aestivation pattern, determines the flower's capacity for reproduction and survival.

Vocabulary of Flower Anatomy

Sepals typically form the outermost whorl and serve as protection for the budding flower, while petals are found next, and are often brightly colored to attract pollinators. Stamens, the male reproductive organs, consist of the anther and filament. And, at the center of the flower, the carpels (or pistils) house the ovary, style, and stigma, comprising the female reproductive system. Knowing these parts can help students understand the complex lifecycle of plants and the incredible diversity found in nature.