exam practice

Question 1

describe how the ELISA test works

Answer 1

1. target antigen binds to the bottom of well. First antibody binds to complimentary antigen
2. second antibody with enzyme attached to it is added
3. second antibody binds to the complementary antigen
4. substrate is added, colour change indicates a positive result

Question 2

what cell organelle do both chloroplast and prokaryotes have in common?

Answer 2

ribosomes