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Topic 6: Genetics
1. The transfer of genes from parents to their
offspring is known as
(1) differentiation
(2) heredity
(3) immunity
(4) evolution
2. The diagram below shows a diploid cell with
two homologous pairs of chromosomes.
5. The diagram below represents a reproductive
process that takes place in humans.
Which statement does not correctly describe
this process?
(1) The normal species chromosome number
is restored.
(2) Males and females each contribute DNA
to the offspring.
(3) The zygote will develop to become identical
to the dominant parent.
Due to independent assortment what possible
combinations of alleles could be found in
gametes produced from this cell by meiosis?
(1) Aa, Bb, AA, and bb
(2) AaBb and ABab
(3) AB and Ab, only
(4) AB, Ab, aB, and ab
3. The sorting and recombination of genes during
sexual reproduction is important to evolution
because these processes
(1) decrease variation and help maintain a
stable population
(2) increase variation that enables species to
adapt to change
(3) decrease the chances of producing
offspring that are adapted to the
environment
(4) increase the ability of all the offspring to
adapt to the environment
4. Which genotype illustrates codominance of
alleles that control blood type in humans?
(1) ii
(2) I Ai (3) I BI B (4) IAIB
(4) The sex of the zygote is determined by
DNA in the gametes.
6. In watermelon plants the allele for solid green
fruit (G) is dominant over the allele for striped
fruit (g). Pollen from a flower of a homozygous
green watermelon plant is used to pollinate a
flower from a heterozygous green watermelon
plant. What percent of the offspring of this
cross will bear striped watermelons?
(1) 25%
(2) 50%
(3) 100%
(4) 0%
7. 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?
(1) BB × Bb
(2) Bb × bb
(3) BB × bb
(4) Bb × Bb
8. The genes for red hair and freckles are usually
inherited together because these genes are
(1) homologous
(2) sorted independently
(3) linked
(4) hybrid traits
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Topic 6: Genetics
9. The gene for tallness (T) is dominant over the
gene for shortness (t) in pea plants. A
homozygous dominant pea plant is crossed with
a heterozygous pea plant, and 200 seeds are
produced. Approximately how many of these
seeds can be expected to produce plants that are
homozygous dominant?
(1) 100 (2) 0
(3) 50
13. Base your answer on the graph below and on
your knowledge of biology.
(4) 200
10.A geneticist wishes to determine if a red rose of
a certain variety is homozygous for the color
red. If red is dominant over white, the red rose
should be cross-pollinated with roses of the
same variety that are
(2) homozygous white
If the environment were to change
dramatically or a new plant disease were to
break out, which plant type would most likely
survive?
(3) heterozygous red
(1) wild wheat
(2) domestic wheat
(4) heterozygous pink
(3) wild corn
(4) domestic corn
(1) homozygous red
11.A cross between two plants that have pink
flowers produced plants that have red, pink, or
white flowers. Which is the most likely
explanation for these results?
(1) Intermediate inheritance involved alleles
that were not clearly dominant or recessive.
(2) Mutations occurred during gametogenesis.
(3) Crossing-over of white and red alleles
occurred during meiosis.
(4) Nondisjunction of homologous pairs of
chromosomes resulted in the production
of abnormal offspring.
12. A boy inherits genes for tallness, but his
growth is limited as a result of poor nutrition.
This is an example of
(1) an inherited disorder
(2) environmental influence on gene
expression
14. Several goldfish were kept in a small
aquarium for several years. The fish grew to
be approximately 6 centimeters long in the
first year, and after that, growth in length
stopped. These fish were later transferred to a
large pond. In the pond, the goldfish grew
much larger, reaching lengths of around 25
centimeters. Which statement provides the
best explanation for the increased growth of
the fish in the pond?
(1) Chemicals present in the pond increased
the amount of DNA in the fish, causing
the growth increase.
(2) The expression of genetic information in
the fish was influenced by their
surroundings.
(3) The fish expressed and passed on only
those characteristics that enabled them to
survive in the new environment.
(4) The size of the fish depended only on
their food supply and not on their DNA.
(3) expression of a hidden trait
(4) a characteristic controlled by more than
one pair of genes
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Topic 6: Genetics
15. The diagram below represents the organization
of genetic information within a cell nucleus.
17. The diagram below represents the banding
pattern for human chromosome 11, with some
of the bands labeled.
The circle labeled Z most likely represents
(1) amino acids
(2) chromosomes
(3) vacuoles
(4) molecular bases
16. Which diagram represents a pair of
homologous chromosomes?
The bands represent
(1) proteins
(2) genes
(3) starches
(4) enzymes
18. The diagram below shows a process that can
occur during meiosis.
(1)
The most likely result of this process is
(2)
(1) a new combination of inheritable traits
that can appear in the offspring
(2) an inability to pass either of these
chromosomes on to offspring
(3)
(4)
(3) a loss of genetic information that will
produce a genetic disorder in the
offspring
(4) an increase in the chromosome number
of the organism in which this process
occurs
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Topic 6: Genetics
19. Molecule 1 represents a segment of hereditary
information, and molecule 2 represents the
portion of a molecule that is determined by
information from molecule 1.
21. As a result of sexual reproduction, an
organism can pass a gene mutation to its
offspring if the mutation occurs in
(1) a body cell
(2) a sex cell
(3) liver tissue
(4) white blood cells
22. Mutations that occur in skin or lung cells have
little effect on the evolution of a species
because mutations in these cells
What will most likely happen if there is a
change in the first three subunits on the upper
strand of molecule 1?
(1) The remaining subunits in molecule 1
will also change.
(2) A portion of molecule 2 may be different.
(1) usually lead to the death of the organism
(2) cannot be passed on to offspring
(3) are usually beneficial to the organism
(4) lead to more serious mutations in
offspring
(3) Molecule 1 will split apart, triggering an
immune response.
(4) Molecule 2 may form two strands rather
than one.
20. Which situation would most directly affect
future generations naturally produced by a
maple tree?
(1) Ultraviolet radiation changes the DNA
sequence within some leaves of the tree.
(2) Ultraviolet radiation changes the DNA
sequence within the gametes of some
flowers of the tree.
(3) An increase in temperature reduces the
number of cell divisions in the roots.
(4) Rapidly growing cells just under the bark
are exposed to radiation, causing
changes in genetic material.
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Topic 6: Genetics
Base your answers to questions 23 through 27 on the
diagram below of the chromosomes from a human
cell and on your knowledge of biology.
27. This chromosomal arrangement indicates that
the individual has
(1) phenylketonuria
(2) Down's syndrome
(3) sickle-cell anemia
(4) Tay-Sachs disease
Base your answers to questions 28 through 30 on the
pedigree chart below which shows a history of blood
types.
23. Which procedure can be performed during
fetal development to detect the chromosomal
disorder illustrated by the diagram?
(1) genetic counseling
(2) amniocentesis
28. The blood types of the individuals represented
in the chart by 7 and 8 could be
(3) urine analysis
(1) A or B, only
(4) cloning
(2) AB, only
24. The diagram represents a
(1) deletion
(2) synapsis
(3) karyotype
(4) disjunction
25. The chromosomes are arranged to show
(1) homologous pairs
(2) tetrads
(3) independent assortment
(4) nucleotides
(3) A, B, or AB, only
(4) A, B, AB, or O
29. The genotype of the individual represented in
the chart by 5 is
(1) I aI a (2) Iai
(3) ii
(4) I aI b
30. Which individuals represented by the chart must be homozygous for blood type?
(1) 1 and 2
(2) 2 and 3
(3) 3 and 4
(4) 1 and 4
26. The individual from whom these
chromosomes were taken is a
(1) male
(2) female
(3) hermaphrodite (4) polyploid
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Topic 6: Genetics
31. A mother pregnant with her fourth child
remarked, "This one just has to be a boy. It is
almost certain, since my other three children
are girls." Which statement best indicates the
accuracy of the mother's comment?
33. In the diagram below, strands I and II
represent portions of a DNA molecule.
(1) The mother is wrong because the chance
of having a boy is always 50%.
(2) The mother is wrong because there is
only a 25% chance that the child will be
a boy.
(3) The mother is right because the genes of
the father are dominant over those of the
mother.
Strand II would normally include
(4) The mother is right because a child
usually inherits both sex chromosomes
from the mother.
(1) AGC
(2) TCG
(3) TAC
(4) GAT
32. Three structures are represented in the
diagram below.
What is the relationship between these three
structures?
(1) DNA is made up of proteins that are
synthesized in the cell.
(2) Protein is composed of DNA that is
stored in the cell.
(3) DNA controls the production of protein in
the cell.
(4) The cell is composed only of DNA and
protein.
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Topic 6: Genetics
Base your answers to questions 34 through 36 on the
diagram below and on your knowledge of biology.
The diagram represents molecules involved in
protein synthesis.
37. A scientist claimed that he had cloned a
guinea pig to produce two offspring, a male
and a female. The claim is not valid because
(1) guinea pigs can reproduce both sexually
and asexually
(2) the two offspring are not identical copies
of the original guinea pig
(3) each of the offspring had half the genetic
information of the original guinea pig
(4) none of the genetic information came
from the original guinea pig
34. In eukaryotic cells, molecule 1 is found in the
(1) centriole
(2) nucleus
(3) cell wall
(4) lysosome
35. Where does the production of molecule 3 take
place?
38. In several species of birds, the males show off
their bright colors and long feathers. The
dull-colored females usually pick the brightest
colored males for mates. Male offspring
inherit their father’s bright colors and long
feathers. Compared to earlier generations,
future generations of these birds will be
expected to have a greater proportion of
(1) bright-colored females
(2) dull-colored females
(1) in the vacuole
(3) dull-colored males
(2) on the plasma membrane
(4) bright-colored males
(3) in the lysosome
(4) at ribosomes
36. The building blocks of molecule 3 are known
as
(1) RNA molecules
(2) DNA molecules
(3) fatty acids
(4) amino acids
39. According to the Hardy-Weinberg principle,
the gene pool of a population will remain
stable if
(1) no mutations occur
(2) the population is small
(3) individuals migrate into and out of the
population
(4) nonrandom mating occurs by artificial
selection
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Topic 6: Genetics
Base your answers to questions 40 and 41 on the pedigree chart below. The pedigree chart represents the inheritance of color blindness through
three generations.
40. Which statement about the genotype of Linda and Donna regarding color blindness is correct?
(1) Both carry one recessive allele.
(2) Linda is a carrier, and Donna is homozygous dominant.
(3) Both are homozygous recessive.
(4) Linda is homozygous dominant, and Donna is a carrier.
41. Where is the allele for color blindness carried?
(1) on the Y-chromosome, only
(2) on the X-chromosome, only
(3) on both the X- and Y-chromosomes
(4) on neither the X- nor the Y-chromosome
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Topic 6: Genetics
42. The diagram below represents a process that occurs during normal human development.
Which statement is correct regarding the cells and DNA?
(1) All the cells have identical DNA.
(2) The DNA of the fertilized egg differs from the DNA of all the other cells.
(3) The DNA of the fertilized egg differs from some, but not all, of the other cells.
(4) Only the fertilized egg contains DNA.
Base your answers to questions 43 through 45 on the diagram below, which represents some biochemical reactions involved in a cellular process.
43. The molecule coded directly from DNA is represented by number
(1) 1
(2) 2
(3) 3
(4) 4
44. What is an example of a molecule produced by this type of process?
(1) glucose
(2) glycogen
(3) a fatty acid
(4) a protein
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Topic 6: Genetics
45. What is the bond labeled 5 known as?
(1) a peptide bond
(2) a hydrogen bond
(3) an ionic bond
(4) a carboxyl bond
46. Modern dogs are direct descendants of the gray wolf. They first appeared about 130,000 years
ago. Today, there are about 150 different breeds of domestic dog, a few of which are shown
below.
The great variety of modern dogs can best be explained by
(1) selective breeding of dogs over many years
(2) the cloning of domestic dogs
(3) genetic alterations in gray wolves alive today
(4) natural selection favoring wolves over dogs
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Topic 6: Genetics
Base your answers to questions 47 and 48 on the diagram below and on your knowledge of biology.
47. In the procedure indicated by letter A, DNA segments from humans and bacteria are joined by
the action of
(1) starch molecules
(2) simple sugars
(3) enzymes
(4) hormone
48. Which process is indicated by letter B?
(1) natural selection
(2) mitosis
(3) sexual reproduction
(4) gene deletion
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Topic 6: Genetics
49. The graph below shows the changes in the
number of individuals in a population who
have a specific trait
Which statement concerning this trait is a
valid inference?
(1) As time passed, an increasing number of
individuals with this trait survived and
reproduced.
(2) Individuals can acquire new survival
characteristics over time and pass them
on to their offspring.
(3) The longer a species is in an
environment, the less likely it is that
mutations will occur within the species.
(4) The number of traits a species possesses
has a direct relationship to the amount of
time the species will exist.
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Answer Key
Topic 6-Genetics
1.
2
36.
4
2.
4
37.
2
3.
2
38.
4
4.
4
39.
1
5.
3
40.
1
6.
4
41.
2
7.
4
42.
1
8.
3
43.
1
9.
3
44.
4
10.
2
45.
1
11.
1
46.
1
12.
2
47.
3
13.
1
48.
2
14.
2
49.
1
15.
2
16.
2
17.
2
18.
1
19.
2
20.
2
21.
2
22.
2
23.
2
24.
3
25.
1
26.
1
27.
2
28.
4
29.
2
30.
4
31.
1
32.
3
33.
4
34.
2
35.
4
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