What is the primary function of the lamellae in the gill filaments of fish gills?

• A. To regulate the flow of water over the gills
• B. To increase the surface area for gas exchange
• C. To aid in the digestion of food particles
• D. To protect the gills from debris

Answer: (B)

Verified step by step guidance

1. Understand the structure of fish gills: Fish gills are composed of gill arches, gill filaments, and lamellae. The lamellae are thin, plate-like structures attached to the gill filaments.
2. Recognize the role of surface area in biological processes: In many physiological systems, increasing surface area enhances the efficiency of processes such as gas exchange, absorption, and filtration.
3. Identify the primary function of lamellae: The lamellae in fish gills serve to increase the surface area available for gas exchange, allowing more oxygen to be absorbed from the water and more carbon dioxide to be expelled.
4. Consider the process of gas exchange: Gas exchange in fish occurs as water flows over the gill filaments and lamellae, where oxygen diffuses into the blood and carbon dioxide diffuses out.
5. Eliminate incorrect options: The lamellae do not regulate water flow, aid in digestion, or protect from debris. Their primary function is to maximize the surface area for efficient gas exchange.