In what way do the membranes of a eukaryotic cell vary?
a) some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.
b) phospholipids are found only in certain membranes.
c) only certain membranes of the cell are selectively permeable.
d) only certain membranes are constructed from amphipathic molecules.
e) certain proteins are unique to each membrane.

Agene with the original sequence of atgtt—tact underwent substitution mutation to form atatt—tact after a few generations. tact is a part of a muscle protein encoding region, and atgtt codes for a digestive enzyme. what will be the effect of this mutation? a. the production of muscle protein will be affected. b. the production of digestive enzymes will be affected. c. the production of both the protein and the enzyme will be affected. d. the production of neither the protein nor the enzyme will be affected.

Which of the following is true of photosynthesis? a)carbon dioxide is a reactant b)water is a product c)most reactions within this process are exothermic d)oxygen is a reactant

In what for do plants utilize nitrogen? why do they need nitrogen?