The cell membrane is considered what?
semi-permeable.
porous.
all of the above
fully permeable.

Semi-permeable

Explanation:

Some small, nonpolar molecules can slip right through the membrane such as oxygen and carbon dioxide but larger, polar molecules must go through special protein channels which may require energy to transport molecules through the membrane. Water for example cannot pass through the membrane so it passive transports itself through aquaporins. Glucose also uses protein channels.

Because only certain molecules can diffuse right through the membrane, it is semi-permeable.

a motor homunculus represents a map of brain areas dedicated to motor processing for different anatomical divisions of the body.

homunculus represents the importance of various parts of your body as seen by your brain. as a result, they take up a lot of brain space. although the cortical homunculus is a curiosity, penfield's work in mapping the brain's relationship to the body was invaluable.