Explain why an organism with a similar volume but more spherical in shape would not be as efficient as a flatworm at exchanging substances with their environment.

As the ratio gets smaller, it takes longer for items to diffuse.

Explanation:

When the cell increases in size, the volume increases faster than the surface area, because volume is cubed where surface area is squared.

When there is more volume and less surface area, diffusion takes longer and is less effective. This is because there is a greater area that needs to receive the substance being diffused, but less area for that substance to actually enter the cell.

this is actually why cells divide. When they become too large and it takes too long for them to transport materials across the cell, they lose efficiency and divide in half to raise the surface area to volume ratio.

meiosis is the first to occur after the nuclei of opposite of opposite mating types fuse