The two strands of DNA in the double helix are held to each other ...

[JMatthes]

The two strands of DNA in the double helix are held to each other by ________.
 
  A) covalent bonds
  B) ionic bonds
  C) metallic bonds
  D) dipole-dipole attractions

Question 2

If you have one molecule of CO2, how many molecules of O2 does it contain?
 
  A) None, O2 is a different molecule than CO2.
  B) One, CO2 is a mixture of C and O2.
  C) Two, CO2 is a mixture of C and 2 O.
  D) Three, CO2 contains three molecules.
  E) none of the above

[Jmfn03]

Answer to Question 1

D

Answer to Question 2

A

[JMatthes]

Thank you!

[Jmfn03]

Always glad to help...