Question

part 1: before watching

1. what do you already know about how the flu spreads?
2. do you think viruses are living things? explain why or why not.

part 2: while exploring npr “flu attack!”
(students interact with the npr resource: flu attack! how a virus invades your body)
label or describe these steps of viral infection as you see them in the simulation:

1. entry: how does the flu virus get inside a host cell?
2. takeover: what does the virus do once inside?
3. replication: how does the virus make more copies of itself?
4. release: how does the virus spread to other cells?

Explanation:

1. The flu spreads mainly through respiratory droplets when an infected person coughs, sneezes or talks. It can also spread by touching surfaces contaminated with the virus and then touching the mouth, nose or eyes.
2. Viruses are considered non - living things. They lack the cellular structure and metabolic processes that define life. They cannot reproduce on their own without a host cell.
3. The flu virus enters a host cell by binding to specific receptors on the cell surface, then fusing with the cell membrane or being taken in by endocytosis.
4. Once inside, the virus releases its genetic material (RNA for flu virus) into the host cell's cytoplasm.
5. The virus uses the host cell's machinery (ribosomes, enzymes etc.) to transcribe and translate its genetic material, making viral proteins and new viral RNA copies.
6. Newly formed viral particles are assembled and then released from the host cell, often by causing the host cell to burst (lysis), or by budding out of the cell membrane. These new viruses can then infect neighboring cells.

Answer:

1. The flu spreads through respiratory droplets and contact with contaminated surfaces.
2. Viruses are non - living as they lack cellular structure and independent metabolic processes.
3. It binds to cell surface receptors and enters via fusion or endocytosis.
4. It releases its genetic material into the host cell's cytoplasm.
5. It uses the host cell's machinery to make proteins and RNA copies.
6. It is released by lysis or budding to infect other cells.