5. B) isotonic
6. D) Repressor
7. B) These statements are expressions of the 1st and 2nd energy laws
8. A) making multiple identical copies of small amounts of DNA
9. B) XY (not sure to be honest)
10. C) chlorophylls a and b reflect green light
11. C) amino acids
12. C) a double layer of phospholipids
13. A) a gene located at two different positions on the same chromosome
14. C) proteins
15 - 18 i dont know maybe 18 is A and 16 I C i think the others im not sure.
19. A) an act
20. C) a karyotype