Problem 53 - Objective Biology for NEET

Question

In racemose type of inflorescence, A. Main axis terminates into flower. B. Flower born in basipetal order. C. Main axis not terminates into flower. D. Flower born in acropetal order. (a) A and B only (b) \(\mathrm{C}\) and \(\mathrm{D}\) only (c) A and C only (d) \(\mathrm{B}\) and \(\mathrm{C}\) only

Step-by-Step Solution

Answer

(b) C and D only

Step 1: Understanding Racemose Inflorescence

Racemose inflorescence is a type of floral arrangement where the main axis continues to grow and doesn't end in a flower. The flowers are produced in acropetal order i.e., the youngest flower is at the top and the oldest at the base.

Step 2: Analyzing the Options

Out of the given options, options A and B describe the cymose type of inflorescence where the main axis ends in a flower and the flowers are born in basipetal order. Therefore, these two options are incorrect.

Step 3: Selecting the Correct Option

Since options C and D describe characteristics of racemose inflorescence (i.e., the main axis does not terminate into a flower and flowers are borne in acropetal order), they are the correct options. Thus, the correct answer is (b) C and D only.

Key Concepts

Floral Arrangement

In botany, understanding the concept of floral arrangement is crucial for students, especially in preparing for competitive exams like NEET. Floral arrangement refers to the layout or pattern in which flowers are situated on a plant. Each arrangement gives insights into the reproductive strategy of the plant and can play a role in identification.

Within the context of racemose inflorescence, the flowers are arranged in a way that allows the main axis to continue growing, giving rise to a potentially indefinite number of flowers. This continued growth is fundamental to distinguishing racemose inflorescence from other types, such as cymose, where the main axis ends in a flower. Remember, the pattern of flower arrangement can affect pollination and ultimately, the survival of a plant species.

Acropetal Order

The acropetal order of flower development is an intriguing botanical phenomenon. When discussing inflorescences in plant morphology, the acropetal order signifies that the youngest flowers are formed at the apex or the top of the growing shoot, while the older ones are positioned closer to the base.

In racemose inflorescence, this pattern is observed as the main axis continues to grow and produce new floral buds at its tip. This growth pattern can influence the overall appearance of the flower cluster, and it’s an important concept for botany students, notably for those preparing for exams like NEET, to grasp.

Botany for NEET

For NEET aspirants, botany is an essential subject that covers a wide array of topics, including plant morphology and inflorescences. Mastery of these topics can significantly impact the scores of students in the biology section of the exam. It's advisable for students to familiarize themselves with different types of inflorescences, like racemose and cymose, as questions often test the understanding of these concepts.

On the NEET exam, specifics about flowering patterns, like acropetal and basipetal orders, are frequently examined. By tieing these details to the broader context of plant biology and ecology, students can enhance their ability to recall and apply this knowledge effectively.

Plant Morphology

Understanding plant morphology involves studying the form and structure of plants, which is a critical component of botany. It includes the examination of various plant organs, including leaves, stems, roots, and flowers. Each part has a specific structure that adapts the plant to its environment and plays a role in its survival and reproduction.

Inflorescence, the arrangement of flowers on a plant, is a key morphological trait. The racemose inflorescence is a classic example taught in botany courses, demonstrating how the arrangement and development of flowers can vary within different plant species. This concept goes beyond basic plant anatomy and delves into how these structures function and interact within the plant's lifecycle, an integral part of the study program for NEET.