Question

Amoebas are single-celled eukaryotes found in ponds. Amoebas take in oxygen and release carbon dioxide by diffusion across the cell membrane. These gases are transported throughout the cell by the cytoplasm.

Based on the information above, which of the following best compares structures involved in gas exchange in frogs to structures involved in gas exchange in amoebas?
A.
The lungs act like the cell membrane, and the blood acts like the cytoplasm.
B.
The blood acts like the cell membrane, and the kidneys act like the cytoplasm.
C.
The lungs act like the cell membrane, and the mouth acts like the cytoplasm.
D.
The mouth acts like the cell membrane, and the kidneys act like the cytoplasm.

Answer 1

A. The lungs act like the cell membrane, and the blood acts like the cytoplasm.

Reason: In frogs, gas exchange (O2 in, CO2 out) occurs across the lungs, analogous to diffusion across an amoeba's cell membrane; the blood then transports those gases throughout the frog’s body, analogous to the cytoplasm moving gases within the amoeba.