Chapter 6: DNA and Gene Expression

Question 1

Where in the cell does translation take place?

1. in the cytoplasm
2. in the plasma membrane
3. in the mitochondria
4. in the nucleus

Answer 1

in the cytoplasm

Question 2

The highest percentage of non-coding DNA is found in:

1. viruses.
2. bacteria.
3. humans.
4. archaebacteria.
5. yeast.

Answer 2

humans

Question 3

The mechanism by which the information contained in DNA is coded into a complementary RNA copy is called:

1. translation.
2. replication.
3. the one gene–one enzyme hypothesis.
4. the central dogma.
5. transcription.

Answer 3

transcription

Question 4

The central dogma of molecular biology states that:

1. DNA is transcribed into RNA, which is translated into protein.
2. DNA is translated into protein.
3. DNA is translated into RNA, which is transcribed into protein.
4. RNA is transcribed into protein.
5. DNA is transcribed into RNA.

Answer 4

DNA is transcribed into RNA, which is translated into protein.

Question 5

One of the four nucleotide bases in DNA is replaced by a different base in RNA. Which base is it, and what is it replaced by?

1. guanine, replaced by cytosine
2. thymine, replaced by uracil
3. thymine, replaced by guanine
4. adenine, replaced by uracil
5. cytosine, replaced by guanine

Answer 5

thymine, replaced by uracil

Question 6

The structure of a protein is determined by which of the following?

1. the sequence of nucleic acids it contains
2. the sequence of the amino acids it contains
3. the function of the nucleic acids it contains
4. the number of fatty acids it contains

Answer 6

the sequence of the amino acids it contains

Question 7

Most genes come in alternative forms called:

1. gametes.
2. dominants.
3. recessives
4. alleles
5. chromosomes.

Answer 7

alleles

Question 8

In any DNA molecule, the number of guanine bases is:

1. always equal to the number of thymine bases.
2. always equal to the number of cytosine bases.
3. equal to the total number of cytosine and adenine bases.
4. sometimes equal to the number of thymine bases and sometimes equal to the number of adenine bases.
5. always equal to the number of adenine bases.

Answer 8

always equal to the number of cytosine bases

Question 9

The term “gene expression” refers to:

1. which amino acid is “called for” by a particular codon
2. the role and function of the protein coded for by a gene
3. the total number of genes in an organisms
4. the presence or absence of genes in a particular cell
5. The use of the genetic information to produce a protein.

Answer 9

The use of the genetic information to produce a protein

Question 10

A frameshift mutation is the result of which of the following?
1. One or two nucleotides are added or deleted in a DNA strand.
2. Amino acids are assembled into normal, functional proteins.
3. The DNA is modified in such a way that protein synthesis is unchanged.
4. The substitution of one amino acid for another with similar chemical properties having no effect on protein synthesis.

Answer 10

One or two nucleotides are added or deleted in a DNA strand

Question 11

Which of the following can be said about a frameshift mutation?

a. It changes the reading frame of the protein coding sequence.
b. It must involve the insertion or deletion of nucleotides.
c. It usually doesn’t change the amino acid sequence very drastically.
d. Only a) and b) are correct.
e. None of the above is correct.

Answer 11

Only a) and b) are correct

Question 12

12XX

Question 13

An important difference between mRNA and DNA is:

1. DNA can move outside of the cell, while mRNA stays inside the cell.
2. mRNA can move outside of the cell, while DNA stays inside the cell.
3. mRNA can move throughout the cell, while DNA stays in the cytosol.
4. DNA can move throughout the cell, while mRNA stays in the nucleus.
5. mRNA contains uracil instead of thymine, which is found in DNA.

Answer 13

mRNA contains uracil instead of thymine, which is found in DNA

Question 14

A given section of DNA with the sequence AATGGCTAT is transcribed. What is the corresponding sequence on the mRNA transcription?

1. UUGAACGUA
2. CCGTTAGCT
3. GGTAACTGT
4. TTACCGATA
5. UUACCGAUA

Answer 14

UUACCGAUA

Question 15

Which of the following nucleotide bases are present in equal amounts in DNA?

a. adenine and thymine
b. adenine and guanine
c. guanine and cytosine
d. thymine and guanine
e. Both a) and c) are correct.

Answer 15

Both a) and c) are correct

Question 16

The genetic code is redundant. What does this mean?

1. A gene can be used to produce many mRNA molecules.
2. Most amino acids can be coded for by more than one codon.
3. All organisms use the same genetic code.
4. A specific tRNA molecule can transport more than one kind of amino acid.

Answer 16

Most amino acids can be coded for by more than one codon

Question 17

Which of the following is always the same in every unit of the DNA molecule?

a. the sugar
b. the base
c. the phosphate group
d. Only a) and c) are always the same.
e. Only a) and b) are always the same.

Answer 17

Only a) and c) are always the same

Question 18

In order for translation to occur:
Incorrect Response
1. the nuclear membrane must dissolve.
2. transcription must be occurring simultaneously.
3. a cell must contain a cell wall to which translational protein receptors are bound.
4. there must be large numbers of free amino acids present in the cytoplasm.
5. the DNA must produce large numbers of free amino acids.

Answer 18

there must be large numbers of free amino acids present in the cytoplasm

Question 19

From DNA to protein involves which series of events?

1. transcription, translation
2. transduction, translation
3. translation, transcription
4. reverse-transcription, translation
5. translocation, transcription

Answer 19

transcription, translation

Question 20

The Russian-American biochemist Phoebus Levene was the first to determine that nucleotides may contain one of four different nitrogen-containing bases. Levene believed that the nitrogen-containing bases occurred in equal amounts in DNA. What is the actual proportion of these bases?

1. All four do actually occur in equal amounts. Levene was right.
2. DNA contains twice as much adenine and thymine as guanine and cytosine.
3. DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine.
4. DNA contains equal amounts of guanine and thymine, and equal amounts of adenine and cytosine.
5. DNA contains equal amounts of adenine and guanine, and equal amounts of thymine and cytosine.

Answer 20

DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine