DNA Test Review HELP!?

Question

I did a good chunk of this h.w and I was wondering if you could help me with the rest that i could not understand?

-Thank you

8.What type of bonds is found in the backbone of sides of the molecule? What type of bonds is the rungs?

10. If a strand of DNA has 32% of guanine, how much tymine does it have?

11.What is the name of the enzyme that unwinds the molecule?

12. What is the name of the enzyme that matches the complimentary bases?

13.A person’s genetic code is determined by what?

16. Where do you find DNA in a prokaryotic cell?

18. The differences in the DNA of all organisms are possible due to what?

20. How does DNA replication help us?

21.What can DNA evidence help us to do?

Answer 1

13. The answer is genes

Answer 2

10. 68%

16. plastid

srry thats all i know

Answer 3

13.genes

this is 4 my part, hope to help you a bitt, and good luck

Answer 4

I work in molecualr biology, and some of these questions are dumb.

The "rungs" are presuambly the bonds beween the nucleotides on one strand, and the complimentary strands running along it and opposite.

Those bonds are hydrogen bonds. That's important becuae they are individually weak, you don't need a chemical reaction to break them.  But lots of weak hydrogen bonds along many nucleotides adds up to a strong bond.

I think the answer wanted for 10 is that if the DNA is 32% G, it must also be 32% C.  That leaves 36% to be A and T, so 18% must be T.

I guess for 12 they want DNA poymerase?  13 I guess they want DNA?

DNA in prokaryotic cells is just floating around the cell.  There is no nucleus in prokaryotes.  That's the key to remember.

18 I think they want "mutations".