chapter 5 mastering assignments

Which of the following is the correct mRNA sequence encoded by the DNA sequence: TAC GGT CAC TTC ACT?

AUG CCA GUG AAG UGA

Which of the following describes how 5-bromouracil might create a mutation?

It can replace the base thymine, and can base pair with guanine rather than adenine.

What is the purpose of an anticodon?

It's a region on a tRNA that binds to a complementary codon on mRNA to ensure the proper amino acid is added to a growing protein.

According to the animation, which of the following makes mRNA from the information stored in a DNA template?

RNA polymerase

What type of pre-transcriptional regulation is the most likely to turn off the production of a substance that is already plentiful?

Repressible operons

During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?

T ** During DNA replication, A binds with T.

Which statement about DNA replication is CORRECT?

The leading strand is built continuously, and the lagging strand is built in pieces. ** The leading and lagging strands are the new strands of DNA made during DNA replication. The leading strand is built continuously, and the lagging strand is built in pieces.

Ribosomes contain which of the following?

rRNA

Of the following enzymes, which are correctly matched with their function? To be marked correct, you'll need to select all correctly matched statements, as there may be more than one correct answer.

-Ligase, covalently bonds adjacent Okazaki fragments -DNA polymerase III, builds most of the DNA on the leading and lagging strand

What are the components of a nucleotide? To be marked correct, you'll need to select all applicable components, as there may be more than one correct answer.

-Phosphate -Nitrogen base -A sugar **Nucleotides are the monomers that make up the nucleic acid macromolecule. Nucleotides are composed of a sugar (deoxyribose or ribose), a phosphate, and a nitrogen base (uracil, adenine, thymine, guanine, or cytosine). Histones are used to organize DNA in eukaryotes; they are not a component of nucleotides. (Reference: Figure 5.2, Nucleotides and The nucleic acids DNA and RNA govern cell life.)

How are RNA nucleotides different from DNA nucleotides? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

-RNA nucleotides do not contain thymine. -RNA nucleotides use the sugar ribose, while DNA nucleotides do not. **RNA and DNA are nucleic acids that are composed of nucleotide monomers. RNA and DNA nucleotides all contain phosphate. Purine and pyrimidine nitrogen bases can be found in RNA and DNA nucleotides. RNA nucleotides may contain the nitrogen base uracil, whereas DNA nucleotides may contain the nitrogen base thymine. RNA nucleotides contain the sugar ribose, whereas DNA nucleotides will contain the sugar deoxyribose. (Reference: Figure 5.2, Nucleotides and The nucleic acids DNA and RNA govern cell life.)

Put the following steps of protein synthesis in the order that they occur in a eukaryotic cell: 1- Translation ends at a stop codon 2- RNA polymerase transcribes mRNA from DNA 3- Protein sequence is elongated 4- Translation initiates 5- mRNA is processed and travels to a ribosome

2, 5, 4, 3, 1

Which of the following might result in a frameshift mutation?

Benzopyrene

Which statement about DNA replication is FALSE?

DNA ligase adds nucleotides to the lagging strand. **You're right! This statement is FALSE. DNA ligase seals the gaps between segments of DNA in the lagging strand. It does not add nucleotides to the lagging strand.

The molecule that seals the gaps between the pieces of DNA in the lagging strand is

DNA ligase. ** DNA ligase seals the gaps between the pieces of DNA in the lagging strand, turning it into a continuous strand.

Which of the following is an example of a spontaneous mutation?

DNA polymerase III accidently mismatches a G to a T during Escherichia coli DNA replication, resulting in a silent mutation.

Which of the following build(s) new strands of DNA?

DNA polymerases ** DNA polymerases build new strands of DNA by adding DNA nucleotides one at a time.

The primary flow of genetic information in cells is from

DNA → RNA → protein.

A nucleotide-altering chemical

can alter nitrogenous bases of DNA, resulting in incorrect base pairing.

Which of the following is not directly involved in protein synthesis?

dsRNA

Mutagens

increase the likelihood of mutations in DNA.

Which of the following can be translated into protein?

mRNA

Transcription produces which of the following?

mRNA, tRNA, and rRNA are all produced by transcription.

Thymine dimers result from

nonionizing radiation

Which of the following is involved in bringing amino acids to the ribosomes?

tRNA