Animals were able to increase in size and become multicellular because of the
A) high diffusion rates of oxygen in aqueous media.
B) development of cellular respiration.
C) development of lungs.
D) development of mechanisms for efficient gas exchange and internal transport.
E) maintenance of a good convective flow of fluid past the gas-exchange surface.

Question

Quizplus · Accepted Answer

The development of mechanisms for efficient gas exchange and internal transport allowed animals to grow larger and become multicellular by effectively distributing oxygen and nutrients throughout their bodies.

Animals Were Able to Increase in Size and Become Multicellular