Chapter 10: Gene Expression and Regulation
1. The process of RNA synthesis is called __________.
a. transcription
b. translation
c. replication
d. mutation
2. Information in DNA is carried in __________.
a. the sugar-phosphate backbone of one DNA strand
b. the base pairs between nucleotides in the two DNA strands
c. the proteins that bind to the DNA double helix
d. the order of the nucleotide bases in one DNA strand
3. Both transcription and translation occur in three steps. What happens during the elongation step of each process?
a. During the elongation step of transcription, the RNA molecule is synthesized. During the
elongation step of translation, the protein molecule is synthesized.
b. During the elongation step of transcription, the RNA molecule is stretched out to full length.
During the elongation step of translation, the protein molecule is stretched out to full length.
c. During the elongation step of transcription, synthesis of an RNA molecule is started. During the
elongation step of translation, synthesis of a protein molecule is started.
d. During the elongation step of transcription, the mRNA molecule is completed. During the
elongation step of translation, the protein molecule is completed.
4. The flow of genetic information in cells depends on specific base pairing between nucleotides. Which of the
following correctly matches the type of base pairing with the process of translation?
a. In translation, RNA base-pairs with DNA.
b. In translation, rRNA base-pairs with mRNA.
c. In translation, tRNA base-pairs with rRNA.
d. In translation, tRNA base-pairs with mRNA.
5. The DNA sequence of a codon in a gene was changed from AAT to AAC. This type of mutation is called a(n)
__________. (Refer to Table 10-3 in your textbook.)
a. point mutation
b. insertion mutation
c. deletion mutation
d. neutral mutation
6. The cells in your skin have a different shape and different function from the cells in your liver because the two
types of cells have different __________.
a. DNA
b. proteins
c. lipids
d. carbohydrates
7. Which of the following is NOT a step at which gene expression can be regulated in eukaryotic cells?
a. the rate of transcription
b. the rate of translation
c. the rate of DNA replication
1
d. the types and rates of protein modification
e. the rate of enzyme activity
8. In mammals, males have one X chromosome and one Y chromosome and females have two X chromosomes.
How is the expression of genes on the X chromosome regulated so that there is equal expression of genes on the X
chromosome in males and females?
a. One X chromosome in females is inactivated so that females have only a single X chromosome
capable of transcription.
b. The genes on the X chromosome in males are transcribed twice as fast as in females.
c. All of the X chromosomes are inactivated so that no genes are expressed from the X
chromosome in either males or females.
d. The Y chromosome contains balancing genes that help to raise the levels of mRNA produced by
the X chromosome in males.
9. Some people have eyes of two different colors. What is a possible explanation for this trait?
a. A mutation occurred in the sperm that produced this individual’s embryo.
b. A mutation occurred in the egg that produced this individual’s embryo.
c. A chemical toxin inhibited production of pigment in one eye but not the other.
d. During early stages of development, a mutation occurred in the cell that developed into one of
the eyes, but not other cells in the embryo.
10. The "genetic code" includes __________.
a. units of three bases, each triplet (or codon) corresponding to a single amino acid
b. specific base sequences in the nucleic acids that indicate where to "begin" and "end" the
synthesis of a polypeptide
c. only two bases per amino acid
d. The first two answers are correct.
11. What is the promoter region?
a. It is a region of RNA that binds to the RNA polymerase and initiates transcription.
b. It is a component of each type of RNA.
c. It is responsible for the selective nature of transcription.
d. It is a region of a parent DNA strand that binds to the RNA polymerase and initiates transcription.
12. Which of the following is the first step in translation?
a. bases of the tRNA anticodon bind with the bases of the mRNA codon
b. the formation of a peptide bond between amino acids attached to the adjacent tRNAs on the
ribosome
c. the ribosomal subunits are disassembled
d. stop codons on the mRNA bind to special proteins rather than tRNA molecules
2