Answer to Question 1
Correct Answer: 4
Rationale 1: This is true, but it does not explain why a virus is called an intracellular parasite.
Rationale 2: Most viruses affect only one species of living organism, but this is not why a virus is known as an intracellular parasite.
Rationale 3: This is true, but it does not explain why a virus is called an intracellular parasite.
Rationale 4: Viruses must be inside a host cell to cause infection. They do not have the cellular equipment necessary for self-survival.
Global Rationale: Viruses must be inside a host cell to cause infection. They do not have the cellular equipment necessary for self-survival. Viruses are surrounded by a protein coat called a capsid, typically affect only one species of living organism, and have DNA or RNA, but not necessarily both. These facts do not explain why viruses are called intracellular parasites.
Answer to Question 2
Correct Answer: 4
Rationale 1: This is the role of the viral proteins.
Rationale 2: This does not describe the role of the capsid.
Rationale 3: This does not describe the role of the capsid.
Rationale 4: The role of the capsid is to help the virus attach to the cell membrane of the host.
Global Rationale: The virus is surrounded by a protein coat or capsid, which helps to protect it from the surrounding environment. The structural proteins or glycoproteins that comprise the capsid are arranged in distinct, repeating subunits. These proteins help the virus attach to the cell membrane of its host. Viral proteins facilitate replication of DNA or RNA. Capsids do not allow for release of the viral infection from the host or trigger body defenses to remove the invader.