Ch. 13 HW

In essentially all organisms, the AUG codon codes for: A) the initiation of translation. B) the termination of transcription. C) the termination of chain elongation. D) the amino acid valine. E) a termination tRNA molecule.

A

Substitution of one base pair for another can result in a __________ mutation that results in the conversion of an amino acid specifying codon to a termination codon. A) nonsense B) frameshift C) chromosomal D) missense E) silent

A

The codon is found in the: A) mRNA. B) nontemplate strand of DNA. C) template strand of DNA. D) tRNA. E) rRNA.

A

Transfer RNA carries __________ to the mRNA. A) amino acids B) nucleic acids C) genes D) codons E) nucleotides

A

Frameshift mutations result from: A) the substitution of one base pair for another. B) the substitution of more than one base pair. C) the insertion or deletion of one or two base pairs. D) the substitution of a stop codon for an amino acid-specifying codon. E) the substitution of a start codon for an amino acid codon.

C

One of the mRNA codons specifying the amino acid leucine is 5'-CUA-3'. Its corresponding anticodon is: A) 5'-GAT-3' B) 3'-AUC-5' C) 3'-GAU-5' D) 3'-GAT-5' E) 5'-GAU-3'

C

A mutation that replaces one amino acid in a protein with another is called a __________ mutation. A) frameshift B) recombinant C) nonsense D) missense E) neutral

D

Adenine forms a complementary pair with __________ in RNA and __________ in DNA. A) adenine; thymine B) thymine; adenine C) thymine; thymine D) uracil; thymine E) thymine; uracil

D

The total number of different three-base combinations of the four nucleic acid bases is: A) 12 B) 16 C) 20 D) 64 E) 256

D

RNA DIFFERS from DNA in all of the following EXCEPT: A) RNA is usually single-standed. B) RNA lacks thymine. C) RNA contains uracil. D) RNA contains ribose. E) RNA contains cytosine.

E

RNA synthesis is also known as: A) elongation. B) reverse transcription. C) termination. D) translation E) transcription.

E

Which of the following is made from DNA? A) tRNA only B) mRNA only C) rRNA only D) mRNA and tRNA only E) mRNA, tRNA, and rRNA

E

During protein synthesis, ribosomes: A) attach to the mRNA molecule and travel along its length. B) attach to the DNA molecule and travel along its length to produce an mRNA molecule. C) translate mRNA into tRNA. D) transcribe mRNA to tRNA. E) translate mRNA into DNA.

A

A gene can be defined as: A) a DNA sequence that carries information to produce a specific RNA or protein product. B) a DNA nucleotide sequence that carries information to produce a specific polypeptide. C) a DNA or RNA sequence that carries information to produce a single polypeptide. D) a DNA nucleotide sequence that carries information to produce an enzyme. E) a DNA or RNA sequence that carries information to produce a specific polypeptide.

A

How is the 4-letter language of nucleic acids converted into the 20-word language of amino acids? A) The 4 nucleic acid bases combine in 2-letter combinations that define different amino acids. B) The 4 nucleic acid bases combine in 3-letter sequences that define different amino acids. C) Triplets of the 2-letter nucleic acid bases are translated into the 20 different amino acids. D) The 4 bases each specify 1 amino acid, which give rise to the remaining 16 amino acids. E) The 4 bases are first converted into tRNA molecules, which can each attach to 5 amino acids.

B

What is the mRNA sequence for a strand of DNA reading 5'-CCGTACT-3'? A) 5' GGCAUGA 3' B) 3' GGCAUGA 5' C) 5' GGCATGA 3' D) 3' GGCATGA 5'

B

What type(s) of RNA makes up a portion of the ribosome? A) mRNA B) rRNA C) tRNA D) There is no RNA in a ribosome E) all three kinds of RNA

B

Where is the amino-acid binding site located on the tRNA molecule? A) in the middle of the loop B) at the end of the 3' end of the molecule C) in the first loop D) along the longest stretch of base pairing in the molecule E) on the 5' end of the molecule

B

Why is only one strand of DNA transcribed into mRNA? A) Because mRNA is only required in small quantities. B) Because transcribing both DNA strands would produce different amino acid sequences. C) Because the other strand would produce the same amino acid sequence in reverse order. D) Because all genes are located on the same DNA strand, while the other strand acts as protection E) Because the other strand is transcribed directly into amino acids.

B

Interrupted coding sequences include long sequences of bases that do not code for amino acids. These noncoding sequences, called __________, are found in __________ cells. A) exons; only prokaryotic B) introns; only prokaryotic C) exons; only eukaryotic D) introns; only eukaryotic E) exons; both prokaryotic and eukaryotic

D