Which of the following characteristics is typical of the lytic cycle of a bacteriophage? a) viral dna is incorporated into the host genome. b) the viral genome replicates without destroying the host. c) a large number of phages are released at a time. d) the virus-host relationship usually lasts for generations

The correct answer is: C) A large number of phages are released at a time

Lytic cycle of a bacteriophage is one of the two life cycles of viruses, other being lysogenic. Lytic cycle can be divided in stages:

•Attachment-viruses binds to the receptor on the surface of bacterial cell, usually it uses tail for the attachment

•Entrance-virus injects its genome material (DNA or RNA) into bacteria cell

•Replication and protein synthesis-virus uses mechanism of bacteria to replicate its genome and produce proteins. As a consequence, a huge number of new viruses are formed

•Lysis- viruses express protein for the bacterial lysis (bacterial cell expand and burst) and  hundreds of new phages are released.

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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