Problem 83 - Objective Biology for NEET

Question

External genitalia in cockroach is represented by (a) Male gonophysis (b) Phallomere (c) Ejaculatory duct (d) Both (a) and (b)

Step-by-Step Solution

Answer

The correct answer is (d) Both (a) and (b)

Step 1: Understanding the anatomy of a cockroach

A cockpit diagram of a cockroach shows the different parts of its anatomy. Among the parts mentioned in the options of the exercise, male gonophysis and phallomere are part of the external genitalia. Male gonophysis, also known as phallomeres, are external structures related to copulation. The ejaculatory duct, on the other hand, is an internal structure, not an external one.

Step 2: Identifying the correct choice

With the understanding of the cockroach anatomy, it is clear that both Male gonophysis (a) and phallomere (b) are part of the external genitalia of a cockroach, but not the ejaculatory duct (c).

Key Concepts

Cockroach Anatomy

Understanding the anatomy of a cockroach is crucial for students who study entomology, biology, or are simply curious about these common insects. The physical structure of a cockroach is divided into three main parts: the head, thorax, and abdomen.

The head houses the brain, mouthparts, and sensory organs like the antennae and compound eyes. The thorax bears the legs and wings, with each segment of the thorax having a pair of legs. Cockroaches are known for their ability to scurry quickly, which is aided by their strong legs attached to the thorax. The abdomen is where the reproductive organs are located, including the external genitalia of male cockroaches.

Male Gonophysis

When diving deeper into the reproductive anatomy of male cockroaches, we encounter the male gonophysis. This term is often used interchangeably with 'phallomeres,' which can cause some confusion for students.

The gonophysis is part of the external reproductive structure and plays a critical role in copulation. These components are uniquely designed to transfer sperm to the female during mating. Recognizing that the male gonophysis is not a singular structure but rather a complex of several parts, helps in understanding its function in the reproductive process.

Phallomere

The phallomere is another name for a part of the male gonophysis. It is part of the intricate external genitalia used by male cockroaches during the mating process. These structures are often segmented and somewhat resemble a puzzle, coming together to efficiently transfer sperm to the female.

From the student's perspective, associating the phallomere with its reproductive purpose is a key step in understanding cockroach anatomy. For clarity, it's important to remember that while the word 'phallomere' can refer to one specific part, it is actually a term applied to any of the parts of the male external genitalia.