GCSE Biology - Specialised Exchange Surfaces

The video explains specialized exchange surfaces in organisms, focusing on their role in exchanging substances with the environment. It highlights examples like alveoli in humans and root hair cells in plants. The video outlines common features of these surfaces, such as large surface area, thinness, permeability, and the importance of a good blood supply and external medium. These features facilitate efficient diffusion and maintain concentration gradients necessary for effective exchange processes.

What are the main specialized exchange surfaces in humans?

• Bronchioles and capillaries

• Skin and hair

• Alveoli and villi

• Root hair cells and leaves

Why is a large surface area important for specialized exchange surfaces?

• It increases the thickness of the surface.

• It reduces the need for a concentration gradient.

• It allows for more molecules to diffuse simultaneously.

• It prevents substances from diffusing.

How does the thinness of exchange surfaces benefit diffusion?

• It shortens the distance for diffusion.

• It reduces the need for a blood supply.

• It blocks unwanted substances.

• It increases the surface area.

What does it mean for an exchange surface to be permeable?

• It requires a thick membrane.

• It increases the surface area.

• It blocks all substances.

• It allows substances to diffuse across.

Why is a good blood supply crucial for animal exchange surfaces?

• It reduces the need for external medium.

• It increases the thickness of the surface.

• It blocks unwanted substances.

• It helps maintain a concentration gradient.

What role does the external medium play in exchange surfaces?

• It maintains a concentration gradient.

• It increases the thickness of the surface.

• It blocks diffusion.

• It reduces the surface area.

Which feature is NOT common among specialized exchange surfaces?

• Permeability

• Large surface area

• Thick surfaces

• Good blood supply