1 Cells and Viruses Pre-Assessment

Which of these correctly identifies the two cells described in the table?

• Cell One- Eukaryotic, Cell Two- Prokaryotic

• Cell One- Prokaryotic, Cell Two- Eukaryotic

• Both cells are Prokaryotic

• Both cells are Eukaryotic

Euglena and Paramecium are both single-celled eukaryotic organisms. What characteristic do both share?

• Have a nucleus

• Have ribosomes

• Reproduce sexually

• None of these

Severe 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--

• lysogenic, because the virus is a coronavirus

• lytic, because the virus causes respiratory illness

• lysogenic, because the virus primarily affects older people

• lytic, because of the quick onset of symptoms after infection

A person infected with the human immunodeficiency virus (HIV) may not have any symptoms for a period of time. During this period the virus affects the body by doing which of the following?

• The virus produces toxins that weaken immune cells and prevent them from reproducing.

• The virus damages immune cells while using their machinery to produce copies of itself.

• The virus uses nutrients meant for immune cells to fuel its own cellular respiration.

• The virus changes the identity of the nucleotides of immune cells to prevent the immune system from functioning normally.

Viruses can be transmitted through the air, water, food, insect bites, and direct contact. Once a virus gains entry to the body, it invades a host cell in order to –

• Deactivate the host cell’s defenses

• Synthesize antibodies for defense

• Metabolize host proteins and grow

• Access cellular processes for replication