Options for the question have not been provided. They are as follows:
Substances can pass through them
They are made of muscle
They are located throughout the body
They are made of bone
Answer:
Substances can pass through them
Explanation:
- When a wall or membrane is permeable, it means that substances can pass through it from one side to another.
- Alveoli and capillary have permeable walls.
- Alveoli are found in lungs. They need permeable walls for exchange of gases between the body and the environment.
- Capillaries are a type of blood vessels. They need permeable walls for exchange of nutrients and waste material between the blood and the tissue.
