viruses

Question 1

what type of cell is a virus?

Answer 1

prokaryotic

Question 2

describe the virus lifestyle

Answer 2

stage 1: virus particle reaches a vulnerable host cell and attaches to it using surface proteins.

stage 2: the virus’ genetic material (DNA or RNA) goes inside host cell.

stage 3: the virus’ DNA or RNA takes over the host cell machinery, making lots of copies of itself.

stage 4: after the virus has replicated, the new virus particles break off from the host cell and can go on to infect more cells.

Question 3

state the four components of a virus cell

Answer 3

capsid
viral envelope
attachment proteins
virus genetic material -(DNA or RNA)

Question 4

what’s the purpose of a capsid?

Answer 4

contains the virus’ genetic material

Question 5

what’s the purpose of the attachment proteins?

Answer 5

these help the virus recognise the bind to cells in the host organism

Question 6

what’s the purpose of the virus’ genetic material?

Answer 6

it contains the instructions for making new copies of the virus

Question 7

what’s the purpose of the viral envelope?

Answer 7

its made from fatty lipid molecules taken from cells in the host - protects the genetic material

Question 8

explain why viruses are described as acellular and non living.

Answer 8

acellular - not made of cells, has no organelles.
non living - have no metabolism, cannot independently move or replicate.

Question 9

describe how viruses replicate.

Answer 9

attachment proteins attach to complementary receptors on host cell.
virus injects viral nucleic acid into host cell.
infected host cell replicates virus particles.