1.) Which of the following statements describes purinesand pyrimidines in DNA molecules?

a. purines from hydrogen bonds with purines

b. pyrimidines consist of a one-ring structure

c. pyrimidines form hydrogen bonds with purines.

d. pyrimidines form covalent bonds with purines.

e. Adenine and guanine are pyrimidines

2.) Arrange the steps of DNA replication in the orderthat they occur.

RNA primers are removed

DNA ligase joins DNA fragments together.

Helicase unwinds the DNA double helix

RNA primers are added

Single-stranded DNA-binding proteins bind to each templatestrand

DNA polymerase synthesizes DNA.

3.) Identify the key structural features of a DNAmolecule.

a. DNA bases are always paired purine with pyrimidine

b. strong ionic bonds and hydrophobic interaction hold DNAtogether.

c. DNA contains the nucleotide bases adenine, thymine, guanine,cytosine, and uracil.

d. DNA is most often found as a left-handed helix, commonlyreferred to as A-DNA.

e. DNA strands are antiparallel and include a 5' end and a 3'end.

f. The backbone of DNA is made of a sugar and a phosphatemolecule.

4.) The diagram depicts DNA that is undergoingreplication. Lable the components of the replicationprocess.

5.) The following diagram depicts the general structureof DNA, and a single nucleotide is circled. Label the diagram withthe names of the three components of a nucleotide.

6.) Choose the DNA nucleotide bases that complementguanine and adenine.

guanine- a. guanine. b. cytosine. c.thymine. or d. adenine.

adenine- a. guanine. b. cytosine. c. thymine. or d.adenine.

7.) Classify each mutation example as definitelypositive, definitely negative, or most likely netural. Eachcategory has two examples.

8.) Identify the statements that describe the structureof DNA.

a. The five-carbon sugar of DNA is called ribose.

b. A DNA double helix contains two sugar-phosphate backbonesoriented in opposite directions.

c. Adenine is paired with thymine, and guanine is paired withcytosine.

d. The five-carbon sugar of DNA is called deoxyribose.

e. Adenine is paired with cytosine, and guanine is paired withthymine.

9.) Which enzyme separates the two complimentary strandsof DNA during DNA replication?

a. ligase

b. primase

c. DNA polymerase

d. helicase

10.) an altercation in the nucleotide sequence of a genecan alter the gene product. Each sentence below is made up ofthree-letter words, representing mRNA codons.

THE FAT CAT SAT

THE CAR WAS RED

THE DOG RAN

The same sentences are written below with asubstitution, deletion, or insertion, much as a gene may have asubstitution, deletion, or insertion mutation. Identify whichsentence represents a substitution, which represents a deletion,and which represents an insertion.

leading Okazaki lagging RNA strand fragment strand primer INHA 13' 15' 5 3' 5'