Mutations in dna may result from all of the following except: a. chemical mutagens. b. introduction of a base analog into dna. c. physical insults on the cell, such as uv light. d. spontaneous mutations due to errors in replication. e. all are true

Option E

Explanation:

Mutation can be defined as the change in the sequence of DNA, either due to mistakes that takes place during replication or because of environmental factors.

The cause of mutation can be chemical mutagens, UV exposure, spontaneous mutation during replication, introduction of analog base pair.

Mutation can be positive or negative, but most of the time its effect is negative.

Hence, the correct answer is option E

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

read more on -

oceans

indian ocean

pacific ocean

atlantic ocean

arctic ocean

southern ocean