MRS GREN is an acronym often used by students to help them remember all the features of living organisms.

Choose three of these features and explain what they mean.

COVID-19 an infectious disease caused by a virus. 

Viruses, like the COVID-19 virus, are not classified as living things.

Give three reasons why.

Bacteria can also cause disease in humans, other animals and even plants, but their structure is very different from the structure of viruses.

Name three structures that are present in bacteria but that are not in viruses.

BSE is a disease of cows. BSE damages the cow's brain and spinal cord. 

A cow with BSE lacks coordination, and acts very nervous or violent, which is why BSE is commonly called “mad cow disease”.

BSE is caused by a protein called a prion. 

The body of a sick cow does not recognise the abnormal prion so it is unable to fight off the disease.

Name two ways in which prions are different from viruses.

Humans are organisms from the kingdom Animalia.

 Name two other kingdoms.

Name two characteristics that place humans in the kingdom Animalia.

Humans eat some plants, like lettuce.

Name two characteristics that place a lettuce plant in the kingdom Plantae.

Living things are divided into five kingdoms: animals, plants, fungi, protoctists and prokaryotes.

Which kingdom do unicellular eukaryotes belong to?

Which kingdoms do multicellular eukaryotes with a cell wall belong to?

Which kingdom do multicellular eukaryotes without a cell wall or chloroplasts belong to?

Which kingdom do organisms without a nucleus or membrane-bound organelles belong to?