Animal Viruses

Animal viruses, such as the RNA retrovirus shown here infecting an animal cell, are responsible for a variety of diseases such as AIDS. The retrovirus releases an RNA molecule, shown in yellow, into a cell, where it is reverse transcribed into DNA and inserted into the cell’s chromosome, shown in red. The DNA is then transcribed into many viral RNA molecules, which are encapsulated by the host’s lipid bilayer upon release.

Question 1: What is a retrovirus?
  1. An ancient virus
  2. A virus that attached via the head-portion of the capsule
  3. A virus containing DNA
  4. A virus containing RNA

Answer 1

Answer - (d) A virus containing RNA

Question 2: The RNA molecule from a retrovirus is __________ into DNA and inserted into the cell's chromosome.
  1. translated
  2. reverse transcribed
  3. copied
  4. multiplied

Answer 2

Answer - (b) reverse transcribed

Question 3: Viral RNA molecules are encapsulated by the host's __________.
  1. protein layer
  2. water layer
  3. active enzymes
  4. lipid bilayer

Answer 3

Answer - (d) lipid bilayer