How do electrons gain energy in photosystem 1?

a. they absorb photons.
b. they use energy in the form of glucose.
c. they take energy from atp molecules.
d. they use energy from a hydrogen ion pump.

Which statement about dna replication is true? a. eukaryotes only have one circular chromosome that unwinds at multiple locations. b. eukaryotes can only replicate one segment of a chromosome at a time. c. prokaryotes can only replicate their single circular chromosome in the nucleus. d. prokaryotes only have one origin of replication to initiate replication.

Depending on the organism the number of in a cell may change

Which phrase is the best summary of the model shown? a. the transfer of the sun's energy through trophic levels b. a series of aerobic and anaerobic reactions c. a transformation of light energy into chemical energy d. the breakdown of food molecules