Ice floats in water because it
a) is less dense than water
b) contains more oxygen than water
c) has a higher ph than water
d) has more surface tension than water

What are the doorways into and out of cells, attached to the membrane, and built in the rough er.

True or false: (a) the strings of little red dots represent carbohydrates. (b) the model is called a bilayer because there are two main types of molecules present, lipids and proteins. (c) the many black lines represent amino acid tails. (d) this model shows membrane transport. (e) the blue ovals are hydrophobic. (f) the blue ovals represent phospholipid heads.

Everything in the universe originated from a single point. how was it possible for everything in the universe to have occupied a single point in space?