Question

Secrete acute respiratory syndrome (SARS) is an illness caused by a coronavirus. Symptoms including a high fever, headaches, and body aches typically occur two to seven days after infection by the virus. SARS is more serious in elderly patients. This information suggests that the reproductive cycle of the SARS virus is –

a. Lysogenic, because the virus is a coronavirus
b. Lytic, because the virus causes respiratory illness
c. Lysogenic, because the virus primarily affects older people
d. Lytic, because of the quick onset of symptoms after infection

Answer 1

Answer: Lytic, because of the quick onset of symptoms after infection

Explanation: As seen in the question above, the SARS virus tends to develop symptoms very quickly when it is infecting a person. This speed in the development of symptoms is a characteristic of the lytic cycle, in relation to the reproductive cycle of viruses. This is because in the lytic cycle, a virus can infect many cells at once, which accelerates the development of the disease. This cycle allows the virus to use all of the cell's biological machinery to reproduce more copies of the virus. When these copies are ready, the virus causes the destruction of the host cell and the release of new viruses to other cells, where the whole process will be repeated. This is all done very quickly.

The lysogenic cycle does not cause the rapid infection of thousands of cells, since it is necessary that there is an adaptation between the DNA of the cell and the DNA of the virus. This slows down the infection process and, therefore, symptoms appear more slowly.

Answer 2

The answer to this question is “d”.