Question

part 3: deep thinking questions

1. compare viruses to cells: how are they similar? how are they different?
2. why do scientists often say viruses are nonliving until they enter a host?
3. how does the flu virus affect homeostasis in your body?
4. your immune system responds to the flu. what cells or processes are involved in fighting back?
5. vaccines expose your body to part of the virus (like proteins). how does this help protect you from future infections?
6. antibiotics kill bacteria. why don’t antibiotics work against viruses like the flu?
7. based on what you learned, why is it important to wash hands and cover your mouth when you cough?

part 4: reflection (exit ticket)

• write a short paragraph answering: what makes viruses unique compared to living cells, and why does that make them such a challenge to human health?

Explanation:

1. Similarities and differences between viruses and cells: Viruses and cells both have genetic material (DNA or RNA). However, cells are living, self - sufficient units with organelles, while viruses are acellular, non - living outside a host, and lack most cellular machinery.
2. Viruses as non - living until entering a host: Viruses cannot carry out metabolic processes, reproduce, or maintain homeostasis on their own. They rely on a host cell's machinery to replicate and function.
3. Flu virus and homeostasis: The flu virus disrupts homeostasis by causing symptoms like fever (altering body temperature regulation), fatigue (affecting energy balance), and respiratory distress (impairing gas exchange).
4. Immune system response to the flu: White blood cells such as lymphocytes (T - cells and B - cells) and macrophages are involved. B - cells produce antibodies, T - cells help coordinate the immune response and kill infected cells, and macrophages engulf and destroy pathogens.
5. Vaccine protection mechanism: Vaccines expose the body to viral antigens (like proteins). This triggers the immune system to produce memory B - cells and T - cells. When the actual virus infects the body later, these memory cells quickly recognize and mount a strong immune response to prevent or reduce the severity of the infection.
6. Antibiotics and viruses: Antibiotics target bacterial structures and processes such as cell walls, protein synthesis, or DNA replication. Viruses lack these structures and processes, so antibiotics are ineffective against them.
7. Hand - washing and covering mouth when coughing: Washing hands removes viruses that may be on the hands, preventing them from entering the body through the mouth, nose, or eyes. Covering the mouth when coughing reduces the spread of virus - laden droplets in the air, protecting others from infection.

For the reflection: Viruses are unique as they are non - living outside a host, lack cellular structures, and have a simple structure mainly consisting of genetic material and a protein coat. This makes them a challenge to human health because they can quickly replicate within host cells, mutate rapidly, and are difficult to target with drugs due to their reliance on host cell machinery.

Answer:

1. Similarities: Both have genetic material. Differences: Cells are living with organelles, viruses are acellular and non - living outside a host.
2. Because they can't carry out life processes independently; rely on host cell machinery.
3. Causes symptoms like fever, fatigue, and respiratory distress, disrupting body functions.
4. Lymphocytes (T - cells and B - cells), macrophages; B - cells produce antibodies, T - cells coordinate and kill infected cells, macrophages engulf pathogens.
5. Triggers immune system to produce memory cells that recognize and respond to actual virus later.
6. Antibiotics target bacterial structures/processes that viruses lack.
7. Washing hands removes viruses, covering mouth reduces droplet spread.

Reflection: Non - living outside host, lack of cellular structures, simple structure; replicate fast, mutate easily, hard to target with drugs.