Question

question 8 of 10
which best describes how the common cold spreads in the human body?
a. viruses replicate inside a cell and then burst out of the cell.
b. viruses inject dna into bacteria, which are killed.
c. viruses replicate outside of cells and then enter cells.
d. viruses lie dormant for many weeks without replicating.

Explanation:

The common cold is caused by viruses. Viruses replicate inside host cells. They inject their genetic material (DNA or RNA) into the host cell. For example, in the lytic cycle (a common viral replication cycle), viruses take over the host cell's machinery to replicate. Once enough new virus particles are made, the host cell bursts (lysis), releasing the new viruses to infect other cells. Option B correctly describes this process. Option A is incorrect as viruses don't replicate inside a cell and then enter cells (they first enter, then replicate). Option C is wrong because viruses need a host cell to replicate (they can't replicate outside cells). Option D is incorrect as viruses don't lie dormant without replicating for weeks in the context of common cold spread (they actively replicate in host cells).

Answer:

B. Viruses inject DNA into bacteria, which are killed.