Problem 127 - Objective Biology for NEET

Question

Mantle cavity is a site of (a) Excretion (b) Respiration (c) Both (a) and (b) (d) None of these

Step-by-Step Solution

Answer

The correct answer is: (c) Both (a) and (b).

Step 1: Understand the term 'Mantle Cavity'

The mantle cavity is a key part of the anatomy of mollusks and gastropods, including creatures like snails and clams. It's the space between the mantle and the animal's body. The mantle is a protective layer that covers the animal's body.

Step 2: Identify the functions of the Mantle Cavity

The mantle cavity serves several key purposes in the life of these animals. It's a space where water, or sometimes air, can be taken in and expelled for the purposes of respiration – essentially, it's how these animals breathe. The mantle cavity also serves as an excretion site where waste products are expelled from the animal’s body.

Step 3: Match the functions with the given options

Examining the provided options, it can be understood that the mantle cavity caters to both processes of respiration and excretion, aligning with option (c), which states that the mantle cavity is a site of both excretion and respiration.

Key Concepts

Mantle Cavity

The mantle cavity is an essential part of mollusk anatomy. It refers to the hollow space found between the mantle, which is a protective outer layer, and the body of the mollusk. This cavity plays a vital role in maintaining the overall health and functionality of the mollusk. Within this space, a variety of important physiological processes take place. For instance, the mantle cavity is crucial for both respiration and excretion. These functions are essential for the survival of the mollusks, as they support the exchange of gases and the removal of waste materials from the body. Mollusks, such as snails, clams, and gastropods, rely on their mantle cavity not only for these basic functions but also as a protective housing for important organs. Without this cavity, the efficient management of respiratory and excretory tasks would be compromised.

Respiration in Mollusks

Respiration in mollusks is primarily facilitated through the mantle cavity. Mollusks have adapted to various environments, and as such, their respiratory systems can differ significantly. However, the mantle cavity remains central to the respiratory processes across different species. The cavity allows for the exchange of oxygen and carbon dioxide. Water or air enters the mantle cavity, where oxygen is absorbed by specialized structures like gills or the surface of the mantle. Gills are feathery, highly vascularized organs that increase the surface area for gas exchange.

• In aquatic mollusks, water flows over the gills inside the mantle cavity, supplying the necessary oxygen.
• In terrestrial mollusks, such as some snails, the mantle cavity functions as a lung, drawing in air to facilitate breathing.

By accommodating these respiratory functions, the mantle cavity is integral to mollusks' ability to survive in diverse habitats.

Excretion in Mollusks

Excretion in mollusks is another critical function that takes place within the mantle cavity. To sustain life, mollusks must efficiently remove waste products from their bodies, and this is where the mantle cavity comes into play. The process of excretion in mollusks involves the elimination of metabolic waste materials, primarily ammonia or uric acid, depending on the species and their habitat. Specialized organs called nephridia, which are similar to kidneys in other animals, are involved in this process.

• These organs filter waste from the mollusk's system and prepare it for expulsion into the mantle cavity.
• From there, waste products are ejected into the surrounding environment.

By serving as a central location for excretion, the mantle cavity plays a vital role in maintaining system balance and overall health, allowing mollusks to thrive in their ecological niches.