Answer:
The cell membrane controls what goes in and out by having protein channels that act like funnels in some cases and pumps in other cases. Passive transport does not require energy molecules and happens when a funnel opens in the membrane, letting molecules flow through.
Most macromolecules are polymers of simple molecules (monomers). There is not a great variety of simple molecules, but their structure determines the macromolecule. For example, proteins are macromolecules synthesized from amino acids. There are only 20 amino acids and a great number of proteins made of different combinations of those 20 amino acids.
Answer: B. Mallard ducks have a broad bill and feathers
Explanation:
They burst and leave/ move away
