Download Modern Genetics questions and answer key

Practice
Name: __________________________
MODERN GENETICS
1. Which diagram represents a pair of homologous chromosomes?
A)
B)
C)
D)
8. The diagram below shows some chromosomal alterations.
Which chromosome represents an alteration known as a deletion?
A) 1
B) 2
C) 3
D) 4
9. Base your answer to the following question on the list of genetic
changes. Choose from the list below that is best described by that
statement.
Genetic Changes
(1) Translocation
(2) Addition
(3) Deletion
(4) Gene mutation
2. Which statement is correct concerning hereditary information?
A)
B)
C)
D)
A chromosome is composed of many genes.
A gene is composed of many chromosomes.
Each chromosome carries the same information.
Each gene carries the same information.
3. Which sequence correctly represents the arrangement of structures
containing genetic material, from the largest to the smallest size?
A)
B)
C)
D)
chromosome ® gene ® nucleus
nucleus ® chromosome ® gene
gene ® chromosome ® nucleus
gene ® nucleus ® chromosome
4. Which statement best describes the process of crossing-over?
A) It takes place between homologous chromosomes and results in
new gene combinations.
B) It takes place between nonhomologous chromosomes and results
in an increased gene mutation rate.
C) It takes place between homologous chromosomes and results in an
increased gene mutation rate.
D) It takes place between nonhomologous chromosomes and results
in new gene combinations.
5. Although identical twins inherit exact copies of the same genes, the
twins may look and act differently from each other because
A) a mutation took place in the gametes that produced the twins
B) the expression of genes may be modified by environmental
factors
C) the expression of genes may be different in males and females
D) a mutation took place in the zygote that produced the twins
6. A chromosomal alteration in which one or more pairs of homologous
chromosomes fail to separate normally during meiotic cell division is
known as
A) an addition
C) nondisjunction
B) crossing-over
D) translocation
7. Some weed killers, insecticides, and food additives alter the DNA of
certain cells. Because of this effect, these substances are known as
A) parasites
C) contagions
B) mutagens
D) producers
A chromosomal rearrangement is formed after a section breaks off
from one chromosome and becomes attached to a nonhomologous
chromosome.
A) 1
B) 2
C) 3
D) 4
10.A single gene mutation results from
A)
B)
C)
D)
a change in a base sequence in DNA
recombination of traits
the failure of chromosomes to separate
blocked nerve messages
11. As a result of sexual reproduction, an organism can pass a gene
mutation to its offspring if the mutation occurs in
A) a body cell
C) liver tissue
B) a sex cell
D) white blood cells
12. Phenylketonuria (PKU), a human disease characterized by mental
retardation, results from the
A)
B)
C)
D)
inability to produce a specific enzyme
increased production of several enzymes
nondisjunction of chromosomes
production of poisons by bacteria
13. Which genetic disorder is characterized by a buildup of fatty tissue
in the nervous system?
A) phenylketonuria
C) Down syndrome
B) sickle-cell anemia
D) Tay-Sachs
14. What is a homozygous condition resulting in the formation of
abnormal hemoglobin that distorts certain blood cells known as?
A) hemophilia
C) Tay-Sachs
B) phenylketonuria
D) sickle-cell anemia
15. The weakest bonds in a double-stranded molecule of deoxyribonucleic
acid exist between the
A) deoxyribose sugars
C) nitrogenous bases
B) phosphate groups
D) 5-carbon sugars
Thompson
Practice
Base your answers to questions 16 through 18 on your knowledge of
biology and on the charts below which show human chromosomes
arranged in pairs.
16. The preparation of these charts for individuals A and B is known as
A) microsurgery
C) blood typing
B) karyotyping
D) chemical screening
17. The chromosomes numbered 1 through 22 are known as
A) ribosomes
C) centrosomes
22. Which statement best describes a portion of the molecule
represented below?
A)
B)
C)
D)
It consists of many ribose sugars.
It unites with amino acids in the cytoplasm.
It contains uracil, which functions in protein synthesis.
It consists of alternating phosphate groups and deoxyribose
molecules.
23. The diagram below represents a segment of a gene on two
chromosomes.
B) lysosomes
D) autosomes
18. Which genetic disorder in individual A is indicated by the number of
chromosomes labeled 21?
A) phenylketonuria (PKU)
C) sickle-cell anemia
B) Tay-Sacks
D) Down's syndrome
19. The diagram below illustrates fertilization in a human.
The change in the gene sequence is an example of
A) an insertion
C) a substitution
B) a deletion
D) a replication
24. Which is the sugar component of a DNA nucleotide?
A) adenine
C) glucose
B) deoxyribose
D) phosphate
25. Which molecules are needed to cut and copy segments of DNA?
Which type of individual might result from this fertilization?
A)
B)
C)
D)
a 3n individual
an individual with Down syndrome
a normal diploid individual
a monoploid, colorblind individual
20. In a portion of a gene, the nitrogenous base sequence is
T-C-G-A-A-T. Which nitrogenous base sequence would normally be
found bonded to this section of the gene?
A) A-C-G-T-A-A
C) A-G-C-T-T-A
B) A-C-G-U-U-A
D) U-G-C-A-A-U
21. What do the letters A, G, C, and T represent in nucleotides?
A) phosphate groups
C) nitrogenous bases
B) deoxyribose sugars
D) ribose sugars
A) reproductive hormones
C) antibodies
B) carbohydrates
D) biological catalysts
26. During the replication of a DNA molecule, separation or "unzipping"
of the DNA molecule will normally occur when hydrogen bonds are
broken between what two nucleobases?
A) thymine and thymine
C) adenine and cytosine
B) guanine and uracil
D) cytosine and guanine
27. A cell begins to produce a new type of protein. This is most likely due
to an alteration of the
A)
B)
C)
D)
structure of the cell membrane
sequence of bases in a section of a chromosome
chemical makeup of the cytoplasm
shape of the antibodies produced by the nucleus
Thompson
Practice
28. A mutation occurring in a human can be passed from parent to
offspring when it occurs in a
A)
B)
C)
D)
lung cell, due to exposure to a toxic gas
gamete formed in the ovary
body cell undergoing mitosis
heart cell with chromosome damage
A) vacuole
C) chloroplast
29. What is the complementary messenger-RNA sequence for the DNA
sequence shown below?
A) C-A-A-G-G-U
C) G-U-U-C-C-A
34. The process represented in the diagram occurs on the cell organelle
known as a
B) ribosome
D) mitochondrion
Base your answers to questions 35 through 37 on the diagram below
and on your knowledge of biology. The diagram represents a step in
protein synthesis.
B) G-T-T-C-C-A
D) C-A-A-G-G-T
30. DNA serves as a template for the synthesis of
A) messenger RNA
C) starches
B) cellulose
D) lipids
31. Which statement best describes messenger RNA?
A)
B)
C)
D)
It transfers polypeptides to the nucleus.
It is chemically more complex than DNA.
It has one oxygen atom less than DNA.
It is composed of a single strand of nucleotides.
32. Some events that take place during the synthesis of a specific
protein are listed below.
(A) Messenger RNA attaches to a ribosome.
(B) DNA serves as a template for RNA production.
(C) Transfer RNA bonds to a specific codon.
(D) Amino acids are bonded together.
(E) RNA moves from the nucleus to the cytoplasm.
The correct order of these events is
A) B E A C D
C) B C E D A
B) D A E
D) C B A
C
E
B
D
Base your answers to questions 33 and 34 on the diagram below of a
biochemical process that occurs within cells and on your knowledge
of biology.
35. If a sequence of nitrogenous bases on DNA strand I is
T-A-G-C-C-T-A, the corresponding sequence on the RNA will be
A) A-T-C-G-G-A-T
C) T-A-G-C-C-T-A
B) A-U-C-G-G-A-U
D) U-T-C-G-G-U-T
36. During this step in the process of protein synthesis, information is
passed from
A) DNA strand I to RNA
C) RNA to DNA strand I
B) DNA strand II to RNA
D) RNA to DNA strand II
37. The molecule labeled "RNA polymerase" is classified as
A) a carbohydrate
C) an enzyme
B) a lipid
D) a neurotransmitter
38. The genetic code for one amino acid molecule consists of
A) five sugar molecules
C) three nucleotides
B) two phosphates
D) four hydrogen bonds
39. Amniocentesis is a process that is used to
33. The process represented in the diagram is
A) lipid digestion
C) protein synthesis
B) cell respiration
D) protein hydrolysis
A)
B)
C)
D)
determine the rate of mutation in embryos
examine the phenotypes of fruit flies
detect many genetic disorders in humans before birth
search for polyploid fruit seeds
40. A single strand containing phosphate, ribose, and the bases adenine,
guanine, uracil and cytosine is called
A) DNA
B) RNA
C) enzyme
D) sugar
E) base
Thompson
Practice
41. A eukaryotic cell lacking helicase during DNA replication would
A)
B)
C)
D)
E)
be incapable of proofreading the newly synthesized strand
be unable to terminate elongation
be incapable of unwinding the DNA helix
catalyze the DNA strand at incorrect locations
not seal the Okazaki fragments on the lagging strand
42. During DNA replication, the leading strand is easily distinguishable
from the lagging strand because
A) the leading strand is synthesized 3' to 5'
B) the lagging strand is synthesized in separate pieces called
Okazaki fragments
C) helicases only attach to the leading strand
D) the lagging strand is synthesized 5' to 3'
E) DNA ligase is attached to the leading strand
43. Although eukaryotic cells contain over a thousand times more DNA
than is found in a prokaryotic cell, it only takes a eukaryotic cell a
few hours to copy all of its genetic material because
A) eukaryotic DNA polymerases delete unnecessary material as it
is replicating
B) eukaryotic cells follow the semiconservative model for DNA
replication
C) prokaryotic cells have more than four nucleotide bases
D) eukaryotic cells have more than one replication site along its
chain of DNA
E) eukaryotic cells have shorter segments of DNA
44. Mutations caused by damage to DNA are detected by
A) DNA helicase
C) DNA polymerase I
E) topoisomerase
50. A couple is considering having a child and would like to be tested
beforehand for any chromosomal defects. The best method for this
is
A) amniocentesis
C) gene therapy
E) karyotyping
B) bacterial transformation
D) electrophoresis
Base your answers to questions 51 and 52 on the genetic disorder,
chosen from the list below, that is best described by that phrase.
Genetic Disorders
(1) Tay-Sachs
(2) Phenylketonuria
(3) Sickle-cell anemia
(4) Hemophilia
51. Symptoms resulting from the lack of an enzyme needed for the
normal metabolism of an amino acid
A) 1
B) 2
C) 3
D) 4
52. A disorder characterized by crescent-shaped red blood cells with
abnormal hemoglobin
A) 1
B) 2
C) 3
D) 4
53. Watson and Crick described the DNA molecule as a
A) straight chain
C) double helix
B) single strand
D) branching chain
54. The diagram below represents Watson and Crick's model of DNA.
B) DNA ligase
D) DNA primase
45. Before a genetic message can leave the nucleus of a eukaryotic cell, it
must undergo
A) separation
C) termination
E) transcription
B) promotion
D) translation
46. If a segment of DNA contains the sequence 5'-GAT TTA ATG-3', the
resulting RNA must be
A) 3'-CAU UAA AUC-5'
C) 3'-CTA TTA TAC-5'
E) 3'-GAT TTA ATU-3'
B) 3'-CUA AAU UAC-5'
D) 3'-CAT TAA ATC-5'
47. The anticodon region can be found
A)
B)
C)
D)
E)
The substance indicated by the arrow could be
A) thymine.
C) ribose.
55. Which of the following scientists determined that DNA is the
hereditary material in viruses?
A)
B)
C)
D)
E)
within a tRNA molecule
on the polypeptide chain
within an mRNA molecule
on the large subunit of the ribosome
attached to the end of an amino acid
B) deoxyribose.
D) uracil.
Hershey and Chase (1952)
Griffith (1928)
Watson and Crick (1953)
Morgan (1950's)
Meselson and Stahl (1950's)
48. Which of the following best represents the expression of genes?
A) DNA RNA Protein
C) RNA Protein DNA
E) Protein RNA DNA
B) DNA
D) RNA
Protein RNA
DNA Protein
49. The end products of translation are
A) DNA
C) lipids
E) polypeptides
B) RNA
D) amino acids
Thompson
Answer Key
review Modern Genetics
1.
B
43.
D
2.
A
44.
C
3.
B
45.
E
4.
A
46.
B
5.
B
47.
A
6.
C
48.
A
7.
B
49.
E
8.
D
50.
E
9.
A
51.
B
10.
A
52.
C
11.
B
53.
C
12.
A
54.
A
13.
D
55.
A
14.
D
15.
C
16.
B
17.
D
18.
D
19.
B
20.
C
21.
C
22.
D
23.
C
24.
B
25.
D
26.
D
27.
B
28.
B
29.
C
30.
A
31.
D
32.
A
33.
C
34.
B
35.
B
36.
A
37.
C
38.
C
39.
C
40.
B
41.
C
42.
B