Viruses - Check for Understanding

Although viruses do not consist of cells, biologists consider them to be living because they are capable of reproduction.

• True

• False

Once a virus enters either a lytic or a lysogenic cycle, it cannot change to the opposite type of cycle.

• True

• False

In which type of cell cycle(s) does viral DNA become integrated into the host cell's DNA?

• lytic

• lysogenic

• neither lytic nor lysogenic

• lytic and lysogenic

All viruses have

• cytoplasm

• ribosomes

• mitochondria

• none of the above

The capsid of a virus is the

• protective outer coat

• cell membrane

• nucleus

• cell wall and membrane complex

Antibiotics are ineffective against viral infections because

• Viruses are protected inside their host cells.

• Viruses have enzymes that inactivate the antibiotics.

• Antibiotics interfere with metabolic processes that viruses do not perform.

• Viral protein coats block the antibiotics from entering the virus.

Which of the following human activities is most closely associated with emerging viruses?

• absence of a vaccination program

• crowded living conditions

• clearcutting of forests

• Eating uncooked meat

Some viruses are thought to induce ________, a disease characterized by uncontrolled cell division.