LSAT 110 | Section 3 | Logical Reasoning: Q22

LR Question 22 Explanation

QUESTION TEXT: Viruses can have beneficial effects. For example…

QUESTION TYPE: Must be False

FACTS:

1. Viruses can help humans.
2. For example, some viruses kill more-complex microorganisms that can sometimes hurt humans.
3. Viruses have very simple structures. Even small alterations can make them very deadly.
4. Random mutations big enough to make viruses deadly often happen. So any virus could easily become dangerous to humans.

ANALYSIS: The right answer is based on the second point.

___________

1. This could happen. It’s easy for the helpful viruses to become deadly and the deadly viruses to become helpful through mutation.
2. This could happen. We aren’t told how likely it is that more complex organisms mutate.
3. This could be. We only know that some of those micro-organisms are deadly to humans. 
4. This could be true. Those viruses could kill deadly micro-organisms, for example.
5. CORRECT. This cannot be true. We know that at least some viruses help humans by killing more complex micro-organisms. It’s the second sentence.