6. How many lone pairs of electrons would be shown in the Lewis structure of Boron Trifluoride, BF3? a. 0 Lone Pairs b. 3 Lone Pairs c. 6 Lone Pairs d. 9 Lone Pairs e. 12 Lone Pairs f. None of the Above

A circular double-stranded DNA molecule contains 4200 base pairs. In solu- tion the molecule is in a B-form helix, with about 10.5 base pairs per turn. The DNA circle has 12 superhelical turns. What is its superhelix density o?

Which statement best explains the chemical differencesbetween DNA and RNA? (a) DNA has two different sugarsin its sugar–phosphate backbone, but RNA only has one.(b) Thymine is one of the DNA bases, whereas RNA’s correspondingbase is thymine minus a methyl group. (c) TheRNA sugar–phosphate backbone contains fewer oxygenatoms than DNA’s backbone. (d) DNA forms double helicesbut RNA cannot.

3. Classify the following as a lipid, carbohydrate, or amino acid: (EOCQ 58) CH,OC(CH,)12CH, CHOC(CH,),,CH, CH,0C(CH,),CH=CH(CH,),CH, a.