Viruses, host cells and transmission

≈ 48 min

Viruses, host cells and transmission

A virus carries genetic instructions inside a protein coat and sometimes a lipid envelope. It cannot make proteins, release energy or reproduce alone. Infection begins when a virus attaches to a host cell with a matching receptor, enters or injects its genetic material, and redirects the cell's machinery. Transmission describes how a virus moves between hosts; replication describes what happens inside a cell. Those are connected but different scales of explanation.

Work it through

If a virus can bind only to receptors on respiratory cells, it is more likely to affect the airways than skin cells. A cough can move virus-containing droplets to another person; that is transmission, not replication.

Mastery target

Trace a viral infection from host entry to release without treating a virus as a cell.

Why must a virus use a host cell to reproduce?

It lacks cellular machinery for protein synthesis and energy transfer.

It is always smaller than a bacterium.

It has no genetic material.

It cannot enter a body.

Name the key biological term from Viruses, host cells and transmission: enter the term that best fits the explanation and visual model.

Which change would most directly reduce droplet transmission in a crowded indoor space?

Improving ventilation and keeping distance when ill

Taking antibiotics before class

Adding sugar to drinking water

Classifying all microbes as harmful

Which statement corrects a common misunderstanding in Viruses, host cells and transmission?

Correct: Antibiotics target bacterial structures or processes; they do not cure viral infections.

A single observation is enough to prove every biological claim.

Scientific terms are interchangeable whenever they sound similar.

A process always has exactly the same result in every environment.