Question

The adult frog does not respire through (a) Buccopharyngeal cavity (b) Gills (c) Skin (d) Lungs

Short answer

The correct answer is (b) Gills.

Step-by-step solution

Understand the Respiratory Systems of Frogs

Research and understand how frogs breathe. Adult frogs respire (breathe) through three different methods: lungs, the lining of the mouth or buccopharyngeal cavity and their skin.

Identify the Incorrect Option

According to the question, the option which isn't a respiratory method of an adult frog needs to be found. Accordingly, 'buccopharyngeal cavity', 'skin', and 'lungs' are methods through which frogs respire. Therefore, the incorrect option is 'gills'.

Key concepts

Gills

Gills are a vital part of the respiratory system in many aquatic animals. However, when it comes to adult frogs, gills are not utilized in their mature stage of life. Gills are primarily used by tadpoles, which are the larval form of frogs.
These young frogs rely on gills for respiration when they live in water. As tadpoles, frogs are dependent on their aquatic environment to extract oxygen as they have yet to develop lungs. Once they undergo metamorphosis and become adults, frogs lose their gills.
This transformation allows them to adapt to life on land and switch to more terrestrial breathing methods. Hence, adult frogs no longer use gills for their respiratory needs.

Buccopharyngeal Cavity

The buccopharyngeal cavity is an intriguing part of a frog's respiratory system. It refers to the lining of the mouth, which plays a crucial role in the frog's breathing process. Adult frogs use this cavity to respire by a process called buccal pumping.
This involves the rhythmic movement of the floor of the mouth to create airflow. Oxygen is absorbed across the highly vascularized lining of the mouth, while carbon dioxide is expelled. The process is often subtle, with minimal visible movement.
Despite not being as prominent as lung or skin respiration, the buccopharyngeal cavity provides an additional pathway for gas exchange, aiding in the frog's survival.

Respiration Methods

Frogs employ multiple methods of respiration throughout their life cycle. Understanding these methods highlights their adaptability to various environments. In their adult form, frogs rely on lungs for breathing, especially when on land. Lungs allow for efficient gas exchange, similarly to how humans respire.
Another method prominent in frogs is cutaneous respiration, where they breathe through their skin. This method is highly effective due to the thin, permeable nature of their skin. It enables frogs to absorb oxygen and expel carbon dioxide directly through their skin surface.

• Cutaneous respiration requires a moist skin surface, which is why frogs are commonly found in damp environments.
• The combination of lung and cutaneous respiration makes frogs versatile in both aquatic and terrestrial habitats.

By integrating these respiration methods, frogs maintain adequate oxygen levels, ensuring their survival across diverse settings.