Question

are viruses alive?
name:antonio melendez date: 2/5/25

1. before you begin reading, predict the answer to the following question:

are viruses alive?

1. now, read the article. based on the information provided in the article,

define the following terms.
virus:
host:
mimivirus:

1. what are the 8 characteristics of living things?
2. how do the characteristics of viruses compare to the characteristics of

living things?

1. are viruses alive?

Explanation:

This problem is about determining if viruses are alive, which falls under Biology (a subfield of Natural Science). To answer, we rely on biological concepts:

1. Predicting if viruses are alive: Initially, one might think viruses could be alive as they interact with cells, but we need to check against living characteristics.
2. Defining terms (Virus, Host, Mimivirus):

• Virus: A non - cellular infectious agent made of genetic material (DNA/RNA) and a protein coat, needing a host to reproduce.
• Host: An organism (like a cell) that a virus invades to use its cellular machinery for replication.
• Mimivirus: A large virus that has some features blurring the line between viruses and living things, e.g., it has more complex genes and can be infected by smaller viruses (virophages).

1. 8 characteristics of living things:

• Made of cells (cellular organization).
• Reproduce (either sexually or asexually).
• Grow and develop (follow a life cycle, e.g., from embryo to adult in animals).
• Obtain and use energy (metabolism, like photosynthesis in plants or cellular respiration in animals).
• Maintain homeostasis (regulate internal environment, e.g., body temperature in mammals).
• Respond to stimuli (e.g., plants bending towards light).
• Have DNA (or RNA in some cases, but for living things the main genetic material is DNA) as genetic material and pass traits to offspring (heredity).
• Adapt and evolve over time (change in gene pool based on natural selection).

1. Comparing virus characteristics to living things:

• Cells: Viruses have no cells; living things are cellular.
• Reproduction: Viruses can only reproduce by hijacking host cells (not on their own), while living things reproduce independently (e.g., bacteria divide, animals mate).
• Energy use: Viruses don’t use energy on their own; living things metabolize energy.
• Homeostasis/response to stimuli: Viruses don’t maintain homeostasis or respond to stimuli in the way living things do (no internal regulation or purposeful response).
• Genetic material: Viruses can have DNA or RNA, living things (most) have DNA. But just having genetic material isn’t enough—viruses lack other living traits.
• Growth/development/adaptation: Viruses don’t grow or develop like living things (no life cycle stages of growth), and while they can evolve (change over time due to mutations), it’s a passive process from host - mediated replication errors, unlike the active adaptation of living things.

1. Final answer on if viruses are alive: Based on the 8 characteristics, viruses lack key ones (cells, independent reproduction, energy use, homeostasis, growth/development as living things do). So viruses are not alive—they are non - living infectious agents that rely on hosts to carry out functions associated with life.

Answer:

1. (Prediction example) I predict viruses are not alive (or could be alive, but the correct biological conclusion is they are not).

2.

• Virus: A non - cellular infectious agent with genetic material and a protein coat, requiring a host for replication.
• Host: An organism (cell) invaded by a virus to be used for viral replication.
• Mimivirus: A large virus with complex genetics, infectable by virophages, blurring virus - living thing boundaries.

1. The 8 characteristics of living things are: made of cells, reproduce, grow and develop, obtain and use energy, maintain homeostasis, respond to stimuli, have DNA (heredity), and adapt/evolve.
2. Viruses lack cells, can’t reproduce independently, don’t use energy, don’t maintain homeostasis/respond to stimuli in a living - like way, and don’t grow/develop as living things do. They have genetic material but this alone doesn’t make them alive.
3. Viruses are not alive.