Viruses

Question 1

what are viruses?

Answer 1

viruses are a strand of genetic material (DNA or RNA), surrounded by a protein coat

Question 2

are viruses cells?

Answer 2

no

Question 3

are viruses alive?

Answer 3

no, they do not respire or carry out any of the other normal processes taking place in living organisms

Question 4

how do viruses reproduce?

Answer 4

• by entering a host cell, they take over the ribosomes and enzymes in the cell to make new virus particles
• when many new viruses have been made, the cell dies and the viruses are released to infect new cells

Question 5

can viruses infect other organisms?

Answer 5

viruses can infect all other organisms (e.g. Tobacco Mosaic Virus causes brown patches on leaves by stopping chloroplast production, while Influenza infects humans)

Question 6

what are decomposers?

Answer 6

fungi and some bacteria

Question 7

how do decomposers feed?

Answer 7

by saprotrophic nutrition

Question 8

what is saprotrophic nutrition?

Answer 8

• when decomposers secrete digestive enzymes outside of their cells onto the dead organism
• the dead organism is broken down into small, soluble molecules, which are then absorbed by the decomposer