Julian claims that viruses are alive. His supporting evidence is that viruses use the universal genetic code, are able to reproduce, and can evolve. Which statement would be most useful in an argument against Julian’s claim?
a. Viruses are too small to be classified as living things.
b. Viruses evolve only after many generations.
c. Viruses satisfy only some characteristics of life, not all of them. d. Viruses reproduce only under the proper conditions.
The correct answer and explanation is:
The correct answer is c. Viruses satisfy only some characteristics of life, not all of them.
Viruses are unique entities that exhibit some characteristics of life, but not all of them. While they can reproduce, evolve, and use the universal genetic code, they do not exhibit all the fundamental traits of living organisms. Living things typically have the ability to carry out metabolic processes (e.g., energy production, waste elimination), respond to stimuli, and maintain homeostasis. Viruses, however, lack the machinery to carry out these processes on their own.
A virus needs to infect a host cell in order to reproduce, which means it cannot reproduce independently. This is a key point in the argument against considering viruses as fully alive. Viruses are essentially inert outside of a host and rely on the host’s cellular machinery to replicate and produce new viral particles. Without a host, they cannot perform any biological functions, which distinguishes them from living organisms that can independently carry out life processes.
Additionally, viruses do not grow or develop in the same way that living organisms do. While they can evolve over time through mutations and natural selection, this process is only observable in the context of populations of viruses, not at the level of an individual virus. Because viruses cannot maintain homeostasis or carry out metabolic functions, they cannot be classified as fully alive according to the traditional criteria of life.
In summary, while viruses do exhibit some characteristics commonly associated with life, they lack other essential features, making the statement in option c the most useful in arguing against Julian’s claim.