1) Complex organisms produce sex cells that unite during
fertilization, forming a single cell known as
a) an embryo
c) a gonad
b) a gamete
d) a zygote
GENETICS-1
The changes in foot structure in a bird population on over
many generations are shown in the diagram below.
2) A cell with a diploid chromosome number of 12 divided
two times, producing four cells with six chromosomes each.
The process that produced these four cells was most likely
a) internal fertilization
b) external fertilization
c) mitotic cell division
d) meiotic cell division
3) Which diagram represents a pair of homologous
chromosomes?
4) In minks, the gene for brown fur (B) is dominant over the
gene for silver fur (b). Which set of genotypes represents a
cross that could produce offspring with silver fur from
parents that both have brown fur?
a) Bb x Bb
c) BB x BB
b) BB x bb
d) Bb x bb
5) When a certain pure strain of fruit fly is cultured at a
temperature of 16˚C, all of the flies will develop straight
wings. The offspring of these flies will develop curly wings
when they are
raised at 25˚C. This pattern of development
indicates that
a) acquired characteristics can be passed
from generation to generation
b) curly-winged flies will have straightwinged offspring regardless of the
environment
c) the environment can affect the
expression of certain genes
d) straight-winged flies will have curlywinged offspring regardless of the
environment
6) These changes can best be explained by the concept of
a) evolution
b) extinction
c) stable gene frequencies
d) use and disuse
7) In 1889, August Weismann, a German biologist,
conducted an experiment attempting to produce mice without
tails. He cut the tails off adult mice and then permitted them
to mate. All offspring had long tails. He repeated the
experiment many times, always with the same results. This
experiment helped to disprove the concept of
a) overproduction in a species
b) inheritance of acquired characteristics
c) survival of the fittest
d) struggle for existence
8) In cats, a pair of X-sex chromosomes will produce a
female, while an X- and a Y-sex chromosome will produce a
male. Fur color is controlled by a single pair of alleles. The
alleles for orange fur and for black fur are located on the Xchromosome only. Tortoise shell cats have one allele for
orange fur and one for black fur. Which statement concerning
fur color in cats is true?
a) Only female cats can be tortoiseshell.
b) Only male cats can be tortoiseshell
c) Males need two alleles to have orange fur.
d) Males need two alleles to have black
fur.
9) In humans, Down syndrome is often a result of the
a) disjunction of homologous
chromosomes during meiotic cell
division
b) nondisjunction of chromosome
number 21 in one of the parents
c) combination of an egg and sperm,
each carrying a recessive allele for this
disorder
d) fusion of two 2n gametes during
fertilization
10) Which phrase best describes a human with the
chromosomes represented in the diagram below?
GENETICS-2
13) Which diagram best represents a basic structural unit of
DNA?
a) a female who exhibits Down
syndrome
b) a male who exhibits Down syndrome
c) a female who does not exhibit Down
syndrome
d) a male who does not exhibit Down
syndrome
11) Siamese cats have a genotype for dark fur, but the
enzymes that produce the dark coloring function best at
temperatures below the cat's normal body temperature. A
Siamese cat usually has darker fur on its ears, nose, paws, and
tail, because these parts have a lower temperature than the
rest of its body. If a Siamese cat spends much time outdoors
during very cold weather, darker fur grows in other places on
its body. Which statement is supported by these
observations?
a) Phenotype is influenced by both
heredity and environment.
b) Phenotype is usually determined by
the environment, only.
c) Genotype always has a greater
influence than environment.
d) Genotype is influenced by both
heredity and environment.
12) Which statement best describes messenger RNA?
a) It transfers polypeptides to the
nucleus.
b) It is chemically more complex than
DNA.
c) It has one oxygen atom less than DNA.
d) It is composed of a single strand of
nucleotides.
Base your answers to the next three questions on the diagram
below and on your knowledge of biology.
14) The DNA code for structure 1 is
a) U-U-U
c) A-A-A
b) T-T-T
d) P-H-E
15) Number 2 indicates part of a compound known as a
a) nucleic acid c) lipid
b) polysaccharide d) polypeptide
(protine)
16) Number 3 represents a molecule known as
a) ribosomal RNA
b) transfer RNA
c) an amino acid
d) deoxyribonucleic acid
17) Number 4 represents a
a) gene
c) codon
b) nucleotide
d) sugar
The diagram below shows a portion of a DNA molecule
GENETICS-3
Base your answers to the next three questions on the
information below and on your knowledge of biology.
In 1973, Stanley Cohen and Herbert Boyer inserted a gene
from an African clawed frog into a bacterium. The bacterium
then began producing a protein directed by the code found on
the inserted frog gene.
18) The base sequence of the unlabeled strand shown in the
diagram is most likely
a) G-A-G-T
c) T-C-T-G
b) C-U-C-A
d) C-A-C-U
19) A single gene mutation would most likely to occur if
a) messenger-RNA molecules
temporarily bond to DNA molecules
b) the cytoplasm lacks the amino acids
necessary to synthesize a certain
polypeptide.
c) a base sequence in a DNA molecule is
changed
d) transfer-RNA molecules do not line
up properly on a messenger-RNA
molecule
22) The newly synthesized genetic material in the bacterium
is known as
a) recombinant DNA
b) messenger RNA
c) a gene mutation
d) a multiple allele
23) The procedure used by Cohen and Boyer is known as
a) cloning
b) genetic engineering
c) karyotyping
d) genetic screening
24) Analysis of the DNA from both the frog and the
bacterium would reveal that
a) frog DNA is single stranded, but
bacterial DNA is double stranded
b) frog DNA contains thymine, but
bacterial DNA contains uracil
c) DNA from both organisms is
composed of repeating nucleotide units
d) DNA from both organisms contains
the sugar ribose
Base your answers to the next two questions on the diagram below, which represents some molecules involved in
protein synthesis, and on your knowledge of biology.
20) Which number indicates part of a molecule containing
peptide bonds?
a) 1
c) 3
b) 2
d) 4
21) A molecule that contains many codons is indicated by
a) 1
c) 3
b) 2
d) 4
GENETICS-4
25) Which diagram best represents the formation of a zygote
28) In nucleotides, the letters A, G, C, and T represent
that could develop into a normal human male?
a) phosphate groups
b) deoxyribose sugars
c) nitrogenous base
d) ribose sugars\
Base your answers to the next two questions on the chart
below and on your knowledge of biology.
26) Mutations can be transmitted to the next generation only
if they are present in
a) brain cells
c) body cells
b) sex cells
d) muscle cells
The difference in amino acids indicated in the circled portion
of the diagram below causes a change in the shape of red
blood cells.
29) According to this information, the closest evolutionary
relationship most likely exists between the
a) human and the chimpanzee
b) human and the gorilla
c) chimpanzee and the gorilla
d) horse and the zebra
30) The information in the chart provides data that can help
in the identification of possible evolutionary relationships
from the study of comparative
a) cytology
c) anatomy
b) embryology d) biochemistry
27) What is a probable cause of this difference in the
hemoglobin molecules?
a) the inability to synthesize a specific enzyme,
causing an accumulation of fat
b) the substitution of one kind of nucleotide for
another in a DNA molecule
c) an abnormal metabolism of phenylalanine
d) a recessive allele located on an X-chromosome
GENETICS-5
Base your answers to the next two questions on the diagram below and on your knowledge of biology.
31) The diagram represents a technique that can be used for
a) obtaining a chemical analysis of blood and urine
b) transferring recombinant DNA to a
fetus
c) preventing sickle-cell anemia
d) determining the sex of the fetus
32) The chromosome analysis shown could be used to
identify the presence of
a) Tay-Sachs in the mother
b) phenylketonuria in both the mother
and the fetus
c) Down syndrome in the fetus
d) hemophilia in both the mother and the fetus
Base your answers to the next two questions on the
information below and on your knowledge of biology.
Many squirrels in the city of Syracuse
are black, rather than the typical gray.
This coloration is due to the presence of
a gene that codes for the production of
more melanin than is produced in gray
squirrels.
33) Calculating the relative percentages of black and gray
squirrels and predicting how these percentages may change in
future generations would be an investigation in the field of
a) genetic engineering
b) biotechnology
c) population genetics
d) cytology
34) The relative frequencies of black and gray color in the
squirrel population in Syracuse would tend to remain constant
if
a) the squirrel population is small and
some squirrels migrate out of the city
b) no mutations in genes for color occur and the
squirrels do not mate randomly
c) a large number of squirrels migrate
into the city and random mating occurs
d) the squirrel population is large and no
mutations in genes for color occur
GENETICS-6
41) The correct order of molecules involved in protein
synthesis is
a) messenger RNA, transfer RNA, DNA,
polypeptide
b) DNA, messenger RNA, polypeptide,
transfer RNA
Directions for the next four questions:
c) transfer RNA, polypeptide, DNA,
For each phrase select the type of nucleic acid molecule
messenger RNA, DNA
chosen from, the list below, that is best described by that
d) DNA, messenger RNA, transfer RNA,
phrase. [A number may be used more than once or not at all.]
polypeptide
35) Sometimes a section of a chromosome is lost during
meiosis. This loss results in a change in genetic material
known as
a) a deletion
c) crossing-over
b) replication
d) mutation
Types of Nucleic Acid Molecules
a) DNA molecules, only
b) RNA molecules, only
c) Both DNA and RNA molecules
d) Neither DNA nor RNA molecules
42) Which diagram best represents mitotic cell division?
36) May contain adenine, cytosine, guanine, and
thymine
37) Carry genetic information from the nucleus to the
ribosomes
38) Are present in the nucleus of the cell
39) Consist of chains of nucleotides
A karyotype is shown in the diagram below.
40) Information in this karyotype indicates that the individual
is a
a) female with sickle-cell anemia
b) male with Tay-Sachs disease
c) female with Down syndrome
d) male with phenylketonuria
43) The separation of homologous pairs of chromosomes
during meiosis is known as
a) replication
c) alignment
b) synthesis
d) disjunction
44) The normal diploid chromosome number of the house
mouse, Mus musculus, is 40. How many pairs of homologous
chromosomes would a normal zygote of Mus musculus
contain?
a) 10
c) 40
b) 20
d) 80
45) In humans, the gene for red hair and the gene for freckles
are often inherited together because both genes are located on
the same chromosome. This observation best illustrates the
concept of
a) gene linkage
b) independent assortment
c) dominance
d) hybridization
GENETICS-7
46) A woman who is homozygous for type A blood marries a
50) In the diagram below, which type of change most likely
man who is homozygous for type B blood. All of their
caused the new combination of traits in gametes B and C?
children have type AB blood. This type of inheritance is
known as codominance because
a) some of the children would be
expected to have type 0 blood
b) the allele for type A blood is dominant, and the
allele for type B blood is recessive
a) an alteration in the chemical
c) the allele for type B blood is dominant, and the
composition of a gene
allele for type A blood is recessive
b) a change in the chromosome number
d) the allele for type A blood and the allele for type
due to nondisjunction
B blood are both expressed in the children
c) a change in the chromosome
composition due to crossing-over
In rabbits, the gene for black coat color (B) is dominant over
(mixing)
the gene for white coat color (b). In the cross illustrated
d) an alteration in the number of sugars
below, rabbit number III may have genotype BB or Bb.
in DNA
47) Which cross should be done to help determine if rabbit
number III is heterozygous
a) Cross I with 11 a second time.
b) Cross III with a rabbit having
genotype BB.
c) Cross III with a rabbit having
genotype bb.
d) Cross III with 11.
48) A molecule that has the shape of a doublestranded helix?
a) RNA c) ADP
b) DNA d) ATP
49) A man with normal color vision married a woman with
normal color vision. The father of the woman was colorblind.
If this couple had a daughter, what is the chance this child
would be colorblind?
a) 0% c) 50%
b) 25% d) 100%
51) Overexposure of animals to x rays is dangerous because x
rays are known to damage DNA. A direct result of this
damage is cells with
a) unusually thick cell walls
b) no organelles in the cytoplasm
c) abnormally large chloroplasts
d) changes in chromosome number or
structure
52) Breeders have developed corn with 15-foot stalks and
pumpkins weighing 300 pounds. Which method did these
breeders most likely use to develop these new varieties?
a) regeneration
b) natural selection
c) artificial selection
d) grafting
53) What is the function of transfer RNA molecules in the
synthesis of proteins?
a) They provide nucleotides for
messenger RNA production.
b) They carry genetic instructions to the
nucleus.
c) They pick up and transport amino
acids to the ribosomes.
d) They are chemically changed into
amino acids.
54) Which process can produce a large group of
organisms with identical genotypes?
a) cloning
b) sexual reproduction
c) meiosis
d) external fertilization
55) Which diagram represents a sperm that can unite with a
normal egg to produce a zygote that will develop into a
normal human male embryo?
GENETICS-8
Base your answers to the next three questions on the diagram
below and on your knowledge of biology. The diagram
represents molecular structures involved in protein synthesis.
56) The mutation rates in Drosophila will most likely
increase after exposure to
a) ultraviolet radiation
b) yeast growing on a nutrient medium
c) oxygen gas
d) extremely cold temperatures
57) Scientists conducted a study of identical twins who were
separated at birth and raised in different
homes. They found that in some sets of twins
the individuals showed a marked difference in
intelligence. The most likely explanation for this
difference is that
a) expression of inherited traits can
modify the environment
b) intelligence is a sex-linked trait
c) environment can influence the
development and expression of inherited
traits
d) nondisjunction occurred in the
autosomes of one twin but not the other twin
58) The individuality of an organism is determined by the
a) sequence of nitrogenous bases in
deoxyribonucleic acid
b) number of amino acids in a cell
c) position of the ribosomes on the
endoplasmic reticulum
d) number of nitrogenous bases in a
codon
59) Structure 1 represents
a) part of a polypeptide chain
b) a portion of a DNA molecule
c) a portion of an RNA molecule
d) the building blocks of proteins
60) The DNA code for aspartic acid is
a) C-T-G
c) C-C-T
b) C-C-U
d) C-U-C
61) Proline, methionine, and aspartic acid represent three
types of
a) fatty acids
c) amino acids
b) hormones
d) enzymes
62) Structure 2 is synthesized in the
a) nucleus
c) ribosome
b) vacuole
d) lysosome
63) The gene frequency for a particular trait in a population
was determined to be 80% A (dominant allele) and 20% a
(recessive allele). Fifty years later, the gene frequency was
determined to be 60% A and 40% a. What does this change
indicate about the gene pool?
a) It has remained stable.
b) It is evolving.
c) It has become predominantly
recessive.
d) It lacks mutations.
GENETICS-9
68) Which statement best describes chromosomes
that contain genes for the same characteristics?
a) They are present in a normal gamete.
b) They are homologous.
c) They occur in the same monoploid
65) What will happen if a base sequence of a strand DNA is
cell.
changed from A-T-G to A-T-C?
d) They are linked
a) The m-RNA will be changed from UA-C to U-A-G.
69) What is one difference between mitotic cell --division in
b) The t-RNA will be changed from Uplants and mitotic cell division in
A-C to T-A-C.
animals?
c) The m-RNA will be changed from Ta) Chromosomes are replicated in plants
U-C to T-U-G.
but not in animals.
d) The t-RNA will be changed from Cb) The replicated chromosomes separate
A-U to C-A-C.
in plants but not in animals.
c) A cell plate divides the cytoplasm in
66) The addition, removal, or substitution of nitrogenous
plants but not in animals.
bases in a DNA molecule may be caused by
d) The nuclear membrane reforms in
a) mutagenic agents
plants but not in animals.
b) cloning
c) vegetative propagation
70) Which concept is not associated with the work of Gregor
d) nondisjunction
Mendel?
a) dominance
A student using a compound light microscope to observe a
b) use and disuse
cell saw a number of threadlike nuclear structures such as
c) independent assortment
those shown in the photograph below.
d) segregation
64) The technique known as karyotyping is used to detect
abnormalities in
a) chromosomes c) blood and urine
b) ribosomes
d) amniotic fluid
71) In pea plants, the long-stem trait (L) is dominant and the
short-stem trait (l) is recessive. Two pea plants were crossed,
producing seeds that yielded 165 long-stem plants and 54
short-stem plants. The genotypes of the parent plants were
most likely
a) Ll and LL
c) Ll and Ll
b) ll and ll
d) LL and ll
67) These threadlike structures are composed primarily of
a) fatty acids
c) nucleic acids
b) glucose
d) lipids
72) Identical twins were born with genes for a genetic
disorder that can be controlled by diet. Both twins were
placed on this diet, which excludes a certain amino acid.
However, one twin chose not to follow the diet and
developed the genetic disorder. The other twin followed the
diet and did not develop the disorder. This difference between
the twins illustrates that
a) gene expression is not influenced by
biochemical factors
b) identical twins do not always have the
same genotype
c) gene expression is influenced by the
environment
d) the genetic disorder is inherited by identical
twins, only
The diagram below represents a pair of chromosomes.
GENETICS-10
The Punnett square below shows the cross between two
squash plants.
73) Which diagram best represents the chromatids if only
crossing-over has occurred?
74) Which technique is used to determine whether an adult is
a carrier of the gene for sickle-cell anemia?
a) karyotyping c) urine analysis
b) amniocentesis d) blood screening
75) Homologous pairs of chromosomes are restored a result
of
a) gametogenesis c) germination
b) fertilization d) differentiation
The diagram below represents a pair of homologous
autosomes.
77) Which genetic principle is best illustrated by the
phenotype of the offspring?
a) codominance
b) intermediate inheritance
c) independent assortment
d) dominance
78) In pea plants, the gene for yellow seeds is dominant over
the gene for green seeds. Which procedure can be used to
determine if a plant that
produces yellow seeds is homozygous or
heterozygous?
a) crossing it with plants that are
homozygous for yellow seeds
b) crossing it with plants that are
homozygous for green seeds
c) crossing it with plants that are known to contain
mutant genes
d) exposing it to high doses of radiation
79) The exchange of segments of chromatids during meiosis
is known as
a) gene linkage
b) sex linkage
c) crossing-over (mixing)
d) nondisjunction
80) Which blood type would not appear in the offspring and
of parents who had genotypes IAIB and IAIB?
a) A
c) AB
b) B
d) O
76) The letters B and b represent genes for a certain trait.
These letters also represent
a) different allels for the same gene
b) linked genes
c) genes for sex determination
d) homozygous genes
81) Amniocentesis a process that is used to
a) determine the rate of mutation in
embryos
b) examine the phenotypes of fruit flies
c) detect genetic disorders in humans
before birth
d) search for polyploid fruit seeds
GENETICS STUDY GUIDE SOLUTIONS
1) d
50) c
2) d
51) d
3) 2
52) c
4) a
53) c
5) c
54) a
6) a
55) 2
7) b
56) a
8) a
57) c
9) b
58) a
10) c
59) b
11) a
60) a
12) d
61) c
13) 4
62) a
14) c
63) b
15) d
64) a
16) b
65) a
17) c
66) a
18) a
67) c
19) c
68) b
20) a
69) c
21) d
70) b
22) a
71) c
23) b
72) c
24) c
73) 1
25) 4
74) d
26) b
75) b
27) b
76) a
28) c
77) d
29) a
78) b
30) d
79) c
31) d
80) d
32) c
81) c
33) c
34) b
35) d
36) a
37) b
38) c
39) c
40) c
41) d
42) 1
43) d
44) b
45) a
46) d
47) c
48) b
49) a