Problem 1 - Biology: The Dynamic Science

Question

Which of the following describes a respiratory medium? In the liver the rate of diffusion is high. b. In the brain \(\mathrm{CO}_{2}\) moves from the neurons to the blood. c. In the big toe \(\mathrm{O}_{2}\) moves from blood to tissues. d. Epithelial cells form thin surfaces in the lungs. e. A running brook provides \(\mathrm{O}_{2}\) to fish.

Step-by-Step Solution

Answer

The correct answer is e. A running brook provides \(\mathrm{O}_{2}\) to fish.

Step 1 Identify the Meaning

Identity the meaning of a respiratory medium. A respiratory medium is an environment where gas is exchanged in an organism.

Step 2 Analyze the Choices

Analyze the each of the following options in light of the given definition: a. In the liver the rate of diffusion is high. This does not describe a medium for gas exchange. b. In the brain \(\mathrm{CO}_{2}\) moves from the neurons to the blood. This describes a process of gas exchange, but not the medium through which it happens. c. In the big toe \(\mathrm{O}_{2}\) moves from blood to tissues. Again, this describes a process of gas exchange, but not the medium through which it happens. d. Epithelial cells form thin surfaces in the lungs. This describes the anatomical structure that allows gas exchange, but not the medium itself. e. A running brook provides \(\mathrm{O}_{2}\) to fish. This describes the water in the brook as the medium of gas exchange for fish.

Step 3 Confirm the Answer

So, from the analysis, we can see that only option (e) fits the definition of a respiratory medium. A running brook, where the fish extract oxygen, is indeed a respiratory medium.