GCSE Biology - What Is a Virus? - Examples of Viral Disease (HIV, Measles & TMV) #36

The video explains what viruses are, highlighting their non-living nature and ability to reproduce within host cells. It covers three viral diseases: measles, HIV, and tobacco mosaic virus (TMV). Measles is spread through droplets and causes a rash and fever, but is rare in the UK due to vaccination. HIV is transmitted through bodily fluids and weakens the immune system, leading to AIDS if untreated. Antiretroviral drugs can help manage HIV. TMV affects plants, causing discolored patches that hinder photosynthesis and growth.

What is a unique characteristic of viruses compared to living cells?

• They can reproduce independently.

• They are larger than animal cells.

• They are considered living organisms.

• They use host cells to replicate.

How is the measles virus primarily spread?

• Via insect bites.

• Through direct contact with infected surfaces.

• By droplets from coughs or sneezes.

• Through contaminated water.

What does HIV primarily affect in the human body?

• The digestive system.

• The immune system.

• The nervous system.

• The respiratory system.

What is the main function of antiretroviral drugs in HIV treatment?

• To cure the disease completely.

• To prevent the virus from replicating.

• To boost the immune system.

• To eliminate all symptoms immediately.

What effect does the Tobacco Mosaic Virus have on plants?

• It increases sugar production.

• It causes a mosaic pattern on leaves.

• It strengthens plant growth.

• It enhances photosynthesis.