BIOCHEM

PLEASE ONLY ANSWER IF YOU TRULY UNDERSTAND IT!! I postedthis many times, and people have been giving wrong answers. AlsoONLY answer if you can answer it correctly and FULLY. Also a briefexplanation helps! Thank you!

2) The double helix of B-form DNA is stabilized mostsignificantly by:

A) nonspecific base-stacking interactions between two adjacentbases in the same strand

B) hydrogen bonding between the phosphate groups of twoside-by-side strands

C) covalent bonds between the 3’-end of one stand and the 5’-endof the other

D) hydrogen bonds between the ribose of each strand

3) The DNA oligonucleotide abbreviated 5’-pATCGAC-3’ (the pindicated a phosphate on the 5’-end):

A) has an A at its 3’ end

B) has 6 phosphate groups

C) has a phosphate on its 3’ end

D) violates Chargaff’s rules

4) Which of the following is a palindromic sequence?

A) GGATCC

B) GTATCC

C)GAATCC

D) CCTTCC CCTAGG CATAGG CTTAGG GGAAGG

6) What is the principal effect of UV light on DNA?

A) melting of B-form helices

B) production of T-dimers

C) deamination of cytosine residues

D) oxidation of guanosine residues

7) Chargaff’s rules state that in typical DNA:

A) A = G

B) A = C

C) A + T = G + C

D) A + G = T + C

8) In the Watson-Crick structure of DNA, the:

A) nucleotides are arranged in the A-form

B) 2’-hydroxyl groups in ribose sometimes participate inhydrogen bonding

C) two strands are antiparallel

D) purine content must be the same in both strands

9) The recognition site of some restriction enzymes are listedbelow. Which will not produce a “sticky end”?

A) GA↓ATTC

B) CCC↓GGG

C) C↓TCGCG

D) all will produce “sticky ends”

10) Proteins that cut DNA to unwind it are called:

A) helicases

B) topoisomerases

C) ligases

D) endonucleases