1. Biology
Ch. 12 Review

2. Avery’s experiments showed that bacteria are transformed by
RNA.
DNA.
proteins.
carbohydrates.

3. What did Griffith observe when he injected a mixture of heat-killed, disease-causing bacteria and live harmless bacteria into mice?
The disease-causing bacteria changed into harmless bacteria.
The mice developed pneumonia.
The harmless bacteria died.
The mice were unaffected.

4. What would Hershey and Chase have concluded if both radioactive 32P and 35S were found in the bacteria in their experiment?
The virus’s protein coat was not injected into the bacteria.
The virus’s DNA was not injected into the bacteria.
Genes are made of protein.
Both the virus’s protein coat and its DNA were injected into the bacteria.

5. The figure shows the structure of a(an)
DNA molecule.
amino acid.
RNA molecule.
protein.

6. Which of the following is a nucleotide found in DNA?
ribose + phosphate group + thymine
ribose + phosphate group + uracil
deoxyribose + phosphate group + uracil
deoxyribose + phosphate group + cytosine

7. Because of base pairing in DNA, the percentage of
adenine molecules in DNA is about equal to the percentage of guanine molecules.
pyrimidines in DNA is about equal to the percentage of purines.
purines in DNA is much greater than the percentage of pyrimidines.
cytosine molecules in DNA is much greater than the percentage of guanine molecules.

8. In eukaryotes, DNA is located in the nucleus.
floats freely in the cytoplasm.
is located in the ribosomes.
is circular.

9. During mitosis, the DNA molecules unwind.
histones and DNA molecules separate.
DNA molecules become more tightly coiled.
nucleosomes become more tightly packed.

10. Which of the following include all the others?
DNA molecules
histones
chromosomes
nucleosomes

11. DNA is copied during a process called
replication.
translation.
transcription.
transformation.

12. DNA replication results in two DNA molecules,
each with two new strands.
one with two new strands and the other with two original strands.
each with one new strand and one original strand.
each with two original strands.

13. During DNA replication, a DNA strand that has the bases CTAGGT produces a strand with the bases
TCGAAC.
GATCCA.
AGCTTG.
GAUCCA.

14. RNA contains the sugar
ribose.
deoxyribose.
glucose.
lactose.

15. Unlike DNA, RNA contains
adenine.
uracil.
phosphate groups.
thymine.

16. Which of the following are found in both DNA and RNA?
ribose, phosphate groups, and adenine
deoxyribose, phosphate groups, and guanine
phosphate groups, guanine, and cytosine
phosphate groups, guanine, and thymine

17. How many main types of RNA are there?1 3
hundreds
thousands

18. Which type(s) of RNA is(are) involved in protein synthesis?
transfer RNA only
messenger RNA only
ribosomal RNA and transfer RNA only
messenger RNA, ribosomal RNA, and transfer RNA

19. Which of the following are copied from DNA?
mRNA only
mRNA, tRNA, and rRNA
mRNA and tRNA only
proteins

20. What is produced during transcription?
RNA molecules
DNA molecules
RNA polymerase
proteins

21. During transcription, an RNA molecule is formed
that is complementary to both strands of DNA.
that is identical to part of a single strand of DNA.
that is double-stranded.
inside the nucleus.

22. Which of the following statements is true?
A promoter is part of an intron.
A pre-mRNA molecule is longer than the gene from which the molecule was transcribed.
Introns are sequences of DNA.
Any mRNA molecules made from the same gene are always edited the same way.

23. What does the figure show?
anticodons
the order in which amino acids are linked
the code for splicing mRNA
the genetic code

24. How many codons are needed to specify three amino acids?3 6 9 12

25. Why is it possible for an amino acid to be specified by more than one kind of codon?
Some codons have the same sequence of nucleotides.
There are 64 different kinds of codons but only 20 amino acids.
Some codons do not specify an amino acid.
The codon AUG codes for the amino acid methionine and serves as the “start” codon for protein synthesis.

26. What happens during the process of translation?
Messenger RNA is made from DNA.
The cell uses information from messenger RNA to produce proteins.
Transfer RNA is made from messenger RNA.
Copies of DNA molecules are made.

27. Which of the following terms is LEAST closely related to the others?
intron
tRNA
polypeptide
anticodon

28. During translation, the type of amino acid that is added to the growing polypeptide depends on the
codon on the mRNA only.
anticodon on the mRNA only.
anticodon on the tRNA to which the amino acid is attached only.
codon on the mRNA and the anticodon on the tRNA to which the amino acid is attached.

29. Genes contain instructions for assembling
purines.
nucleosomes.
proteins.
pyrimidines.

30. Which type of RNA functions as a blueprint of the genetic code?
rRNA
tRNA
mRNA
RNA polymerase

31. Which of the following statements is false?
Some genes code for enzymes.
The instructions for making some proteins are not specified by genes.
An organism’s inherited traits depend on proteins.
An organism’s genes determine its inherited traits.

32. A mutation that involves one or a few nucleotides is called a(an)
chromosomal mutation.
inversion.
point mutation.
translocation.

33. Which of the following is NOT a gene mutation?
inversion
insertion
deletion
substitution

34. Which of the following is NEVER a frameshift mutation?
substitution
insertion
deletion
point mutation

35. A promoter is a binding site for DNA polymerase.
binding site for RNA polymerase.
start signal for transcription.
stop signal for transcription.

36. Which of the following statements is true?
A promoter determines whether a gene is expressed.
An expressed gene is turned off.
Proteins that bind to regulatory sites on DNA determine whether a gene is expressed.
RNA polymerase regulates gene expression.

37. If a specific kind of protein is not continually used by a cell, the gene for that protein is
always transcribed.
never expressed.
turned on and off at different times.
not regulated.

38. In E. coli, the lac operon controls the
breakdown of lactose.
production of lactose.
breakdown of glucose.
production of glucose.

39. A lac repressor turns off the lac genes by
binding to the promoter.
DNA polymerase.
binding to the operator.
binding to the lac genes.

40. When E. coli is grown on glucose,
lactose molecules bind to the lac repressor.
the lac repressor binds to the operator of the lac operon.
RNA polymerase binds to the promoter of the lac operon.
the lac genes are transcribed.

41. Which of the following is NOT generally part of a eukaryotic gene?
operon
TATA box
promoter sequences
enhancer sequences

42. Gene regulation in eukaryotes
usually involves operons.
is simpler than in prokaryotes.
allows for cell specialization.
includes the action of an operator region.

43. Specialized cells regulate the expression of genes because they
do not want the genes to become worn out.
cannot control translation.
do not carry the complete genetic code in their nuclei.
do not need the proteins that are specified by certain genes.

44. Hox genes determine an animal’s
basic body plan.
size.
skin color.
eye color.

45. Which of the following statements is false?
Mutations do not occur in hox genes.
Hox genes that are found in different animals are very different from each other.
Hox genes control the normal development of an animal.
Hox genes occur in clusters.

46. Hox genes are regulated by operons. are found in bacteria.
are not found in humans.
determine the location of a dog’s ears.

47. The replication of a DNA molecule results in four copies of the same gene.
True
False

48. DNA is tightly wrapped around nucleosomes.
True
False

49. In eukaryotes, DNA replication proceeds in one direction along the DNA molecule.
True
False

50. If a nucleic acid contains uracil, it is DNA.
True
False

51. The nitrogenous bases in RNA are able to form hydrogen bonds with each other.
True
False

52. During DNA replication, only one strand of DNA serves as a template.
True
False

53. A codon consists of four nucleotides.
True
False

54. The anticodon AGA is complementary to the codon TCT.
True
False

55. Genes determine a person’s eye color by coding for nitrogenous bases that affect eye color.
True
False

56. DNA codes for DNA polymerase.
True
False

57. Without regulatory sites, the expression of a gene would not be controlled.
True
False

58. In prokaryotes, an operon is a group of genes that are operated together.
True
False

59. Gene regulation in eukaryotes is less complex than in prokaryotes.
True
False

60. The TATA box in eukaryotes helps to ensure transcription.
True
False

61. In fruit flies, the hox gene that controls the development of the wings is located before the hox gene that controls the development of the eye and before the hox gene that controls the development of the abdomen.
True
False