In complex multicellular organisms, bulk flow is an important physiologic character. Why is bulk flow a necessary condition of complex multicellularity?
A)Complex multicellularity reflects cell adhesion between cells, and this cannot happen without bulk flow of signaling molecules from the environment.
B)Organisms exhibiting complex multicellularity are large and have cells/tissues that are not in contact with their environment. Systems that can overcome the limits of diffusion must occur for basic physiologic processes to occur.
C)Bulk flow is necessary to move large amounts of liquid through the organism depending on physiologic needs. The tissues can all receive necessary nutrients from the environment, but bulk flow speeds the rate of diffusion.
D)Complex multicellularity is related to the increase in oxygen in the environment. Because bulk flow systems are only related to the delivery of oxygen to tissues, higher environmental oxygen selected for individuals with bulk flow systems.

Question

Quizplus · Accepted Answer

Organisms that exhibit complex multicellularity are too large and cells/tissues are not in contact with the environment. This necessitates systems that can overcome the limits of diffusion for basic physiologic processes to occur. Bulk flow allows for the movement of liquid and necessary nutrients throughout the organism.

In Complex Multicellular Organisms, Bulk Flow Is an Important Physiologic