A feature that may be found in viruses but never in bacteria is A feature that may be found in viruses but never in bacteria is. a. a sensitivity to antibiotics. b. an ability to infect more than one type of host. c. may contain an RNA genome. d. they require a microscope to be viewed.

Option D) they require a microscope to be viewed.

Explanation:

Unlike bacteria, virus is a ultramicroscopic pathogenic particle capable of passing through bacteriological filters. So because, the virus is far much smaller than a bacterium, viewing a virus will always require a microscope (electron microscope to be precise) unlike a bacteria that is even visible in culture plates.

Thus, option D is the answer

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.  

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it's     c       this is a cell (b) with a nucleus (c) containing dna (a). the dna is organized into chromosomes (d). a section of the chromosome that codes for a trait is called a gene (e).