BIO Chapter 10

F/T: Helicases unwind the double helix of DNA by breaking the nitrogen bonds that link the hydrogen bases.

False

F/T: In all living things, DNA replication must occur after cell division

False

F/T: After replication, the nucleotide sequences in both DNA molecules are identical to each other and to the original DNA molecule

True

F/T: DNA polymerases have the ability to check for errors in nucleotide pairings

True

Transfer RNA a. carries an amino acid to its correct codon. b. synthesizes amino acids as they are needed. c. produces codons to match the correct anticodons. d. converts DNA into mRNA.

a. carries an amino acid to its correct codon.

The attachment of nucleotides to form a complementary strand of DNA a. is catalyzed by DNA polymerase. b. is accomplished only in the presence of tRNA. c. prevents separation of complementary strands of RNA. d. is the responsibility of the complementary DNA mutagens.

a. is catalyzed by DNA polymerase.

All of the following are true about the structure of DNA except a. short strands of DNA are contained in chromosomes inside the nucleus of a cell. b. every DNA nucleotide contains a sugar, a phosphate group, and a base. c. DNA consists of two strands of nucleotides joined by hydrogen bonds. d. the long strands of nucleotides are twisted into a double helix

a. short strands of DNA are contained in chromosomes inside the nucleus of a cell.

The enzymes that unwind DNA are called a. double helixes b. DNA helicases c. forks d. phages

b. DNA helicases

The enzymes responsible for adding nucleotides to the exposed DNA template bases are a. replicases. b. DNA polymerases. c. helicases. d. nucleotidases.

b. DNA polymerases.

Transcription proceeds when RNA polymerase a. attaches to a ribosome b. binds to a strand of DNA c. binds to a strand of RNA d.attaches to a promoter molecule

b. binds to a strand of DNA

o (circle) I _________ /\____|________|(rectangle) I I (Hexagon connected to a rectangle) _ Refer to the illustration above. The entire molecule shown in the diagram is called a(n) a. amino acid. b. nucleotide. c. polysaccharide. d. pyrimidine.

b. nucleotide.

The part of the molecule for which deoxyribonucleic acid is named is the a. phosphate group. b. sugar. c. nitrogen base. d. None of the above; DNA is not named after part of the molecule.

b. sugar

Watson and Crick built models that demonstrated that a. DNA and RNA have the same structure. b. the DNA helix is held together by hydrogen bonds. c. guanine forms hydrogen bonds with adenine. d. thymine forms hydrogen bonds with cytosine.

b. the DNA helix is held together by hydrogen bonds.

During Transcription a. proteins are synthesized b. DNA is replicated c. RNA is produced d. translation occurs

c. RNA is produced

Of the four nitrogen bases in DNA, which two are purines and which two are pyrimidines? a. adenine—thymine; uracil—cytosine. b. adenine—thymine; guanine—cytosine. c. adenine—guanine; thymine—cytosine. d. uracil—thymine; guanine—cytosine.

c. adenine—guanine; thymine—cytosine.

The function of rRNA is to a. synthesize DNA b. synthesize mRNA c. form ribosomes d. transfer amino acids to ribosomes

c. form ribosomes

adenine: thymine a. protein: DNA b. Watson: Crick c. guanine: cytosine d. adenine: DNA

c. guanine: cytosine

Which of the following is not found in DNA? a. adenine b. cytosine c. uracil d. none of the above

c. uracil

A nucleotide consists of a. a sugar, a protein, and adenine. b. a sugar, an amino acid, and starch. c.a sugar, a phosphate group, and a nitrogen-containing base. d. a starch, a phosphate group, and a nitrogen-containing base.

c.a sugar, a phosphate group, and a nitrogen-containing base.

During DNA replication, a complementary strand of DNA is made for each original DNA strand. Thus, if a portion of the original strand is CCTAGCT, then the new strand will be a. TTGCATG. b. AAGTATC. c. CCTAGCT. d. GGATCGA.

d. GGATCGA

Which of the following is not true about DNA replication? a. It must occur before a cell can divide. b. Two complementary strands are duplicated. c. The double strand unwinds while it is being duplicated. d. The process is catalyzed by enzymes called DNA mutagens.

d. The process is catalyzed by enzymes called DNA mutagens

DNA differs from RNA in that RNA a. is single-stranded b. contains a different sugar molecule c. contains the nitrogen base uracil d. all of the above

d. all of the above

Purines and pyrimidines are a. bases found in amino acids. b. able to replace phosphate groups from defective DNA. c. names of specific types of DNA molecules. d. bases found in nucleotides.

d. bases found in nucleotides.

Molecules of DNA are composed of long chains of a. amino acids. b. fatty acids. c. monosaccharides. d. nucleotides.

d. nucleotides.

Which of the following is not part of a molecule of DNA? a. deoxyribose b. nitrogenous base c. phosphate d. ribose

d. ribose