2. The gene-chromosome theory states that (1.) chromosomes
from both parents always
have identical genes (2.) homologous
chromosomes do not have alleles
(3.) genes exist at definite loci in
a linear sequence on chromosomes
(4.) Mendel's principles no longer apply
to genetics
3. Which statement best describes the process of crossing over?
(1.) It takes place
between homologous chromosomes and results
in new gene combinations. (2.) It
takes place between homologous chromosomes
and results in an increased gene
mutation rate. (3.) It takes
place between nonhomologous chromosomes and results
in an increased gene mutation rate.
(4.) It takes place between nonhomologous
chromosomes and results in new gene
combinations.
4 White short-horned cattle and Black Angus cattle have been crossed
to produce
offspring with superior beef and
rapid growth qualities. This process of
choosing organisms with the
most desirable traits for mating is known as
(1.) cloning (2.) selective breeding
(3.) biodiversity (4.) genetic engineering
| 5. A structure found in the nucleus of a cell is shown in the diagram at the right. The information contained in the diagram best illustrates the (1.) law of segregation (2.) concept of nondisjunction (3.) theory of natural selection (4.) gene-chromosome theory | |
Use the information provided in the chart below and your knowledge of
the living environment to answer questions 6 and 7 which follow.
| 6. The arrangement of chromosomes in the diagram at the right
is known as a (1.) karyotype (2.) centromere (3.) mutation
rate (4.) genotype
7. If the chromosomes of a female were arranged in chart form like the chromosomes of this male, the chart would (1.) be identical to that of the male (2.) appear different in one chromosome pair (3.) contain more chromosomes (4.) have one-half the number of chromosomes |
 |
8. Mutations can be transmitted to the next generation only if
they are present in (1.) brain cells
(2.) body cells (3.) sex cells
(4.) muscle cells
9. Sometimes a section of a chromosome is lost during meiosis.
This loss results in a change
in genetic material known as (1.)
deletion (2.) replication (3.) crossing over (4.) polyploidy
10. In which situation could a mutation be passed on to the offspring
of an organism?
(1.) Ultraviolet radiation causes skin
cells to undergo uncontrolled mitotic division.
(2.) A primary sex cell in a human forms
a gamete that contains 24 chromosomes.
(3.) The DNA of a human lung cell undergoes
random breakage.
(4.) A cell in the uterine wall of a
human female undergoes a chromosomal alteration.
11. Bacteria that produce colonies containing a red pigment were
distributed on nutrient agar
and exposed to ultraviolet light
for several days. The colonies that developed were red,
with the exception of one colony
that was white. The appearance of this white bacterial
colony most likely resulted from
(1.) codominance (2.) a mutation (3.) synapsis
(4.) multiple alleles
12. Which genetic change is best described by the following statement.
A random change in
the base sequence of DNA
results in an alteration of a polypeptide.
(1.) Translocation (2.)
Deletion (3.) Addition (4.) Gene Mutation
13. Which genetic change is best described by the following statement.
A
chromosomal rearrangement is formed
after a section breaks off from one chromosome
and becomes attached to a nonhomologous
chromosome. (1.) Translocation
(2.) Deletion (3.) Addition
(4.) Gene Mutation
14. Substances that increase the chance of gene alterations are
known as (1.) mutagenic agents
(2.) chromosomal agents
(3.) genetic agents (4.) adaptive agents
15. A gene mutation may be transmitted to offspring if the mutation
occurs within
(1.) an egg cell (2.)
cells of the uterus (3.) muscle cells (4.) blood
cells
16. The mutation rates in Drosophila will most likely increase
after exposure to
(1.) ultraviolet radiation
(2.) oxygen gas (3.) yeast growing on a nutrient medium
(4.) extremely cold temperatures
17. Which change in chromosome structure involves the transfer
of one section of a
chromosome to a nonhomologous
chromosome? (1.) nitrogenous base substitution
(2.) crossing-over of linked genes
(3.) translocation (4.) gene mutation
18. Which statement best describes a chromosomal alteration?
(1.) It never affects the
phenotype of an organism.
(2.) It always produces a recessive genotype in an organism.
(3.) It may affect the phenotype
of an organism. (4.) It never has an effect on the genotype
of an organism.
| 19. The diagram at the right shows some chromosomal alterations.
Which chromosome represents an alteration known as a deletion?
(1.) 1 (2.) 2 (3.) 3 (4.) 4 |
 |
20. A mutation may be passed on to future generations if it occurs
within specialized cells of the
(1.) stomach (2.) pancreas
(3.) liver (4.) ovary
21. An example of a mutagenic agent is (1.) an amino acid
(2.) acetylcholine
(3.) ultraviolet radiation
(4.) maltase
22. A single change in the sequence of nitrogenous bases in a
DNA molecule would most
likely result in (1.) crossing-over
(2.) nondisjunction of chromosomes
(3.) polyploidy (4.) a gene
mutation
23. Some weed killers, insecticides, and food additives alter
the DNA of certain cells. Because
of this effect, these substances
are known as (1.) auxins (2.) meristems (3.) mutagens
(4.) autosomes
24. In a species of plant, the sudden appearance of one plant
with a different leaf structure
would most likely be the result
of (1.) stable gene frequencies
(2.) slow environmental changes
(3.) chromosomal mutations (4.) asexual reproduction
25. 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 (1.)
gene expression is not influenced by biochemical factors
(2.) gene expression is influenced
by the environment (3.) identical twins do not always
have the same genotype (4.)
the genetic disorder is inherited by identical twins, only
| 26. The diagram at the right illustrates what happens to the
fur coloration of a Himalayan hare after exposure to a low temperature.
This change in fur coloration is most likely due to (1.) the effect
of heredity on gene expression
(2.) environmental influences on gene action (3.) the arrangement of genes on homologous chromosomes (4.) mutations resulting from a change in the environment |
 |
27. A garden hose that had been lying on a green lawn for several
days was removed.
Which statement best explains
the presence of yellow grass in the area where the hose
had been? (1.) The lack
of sunlight under the hose altered the genotype of the grass.
(2.) The hose altered genes in
the grass, causing the grass to switch from autotrophic
to heterotrophic nutrition.
(3.) Gene expression is not affected by the environment.
(4.) The lack of sunlight under
the hose affected chlorophyll production.
28. Artificial selection is illustrated by (1.) random mating
taking place in a population
(2.) a gardener producing a new
hybrid by cross-pollinating plants
(3.) the appearance of a new species
on an isolated island
(4.) wind assisting the pollination
of grass in a field
29. Breeders have developed a variety of chicken that has no feathers.
Which methods were
most likely used to produce this
variety? (1.) artificial selection and inbreeding
(2.) regeneration and incubation
(3.) grafting and hybridization
(4.) vegetative propagation and
binary fission
30. When the bacterium Serratia marcescens is grown on a sterile
culture medium in a petri dish
at 30°C, the bacterial colonies
will be cream colored. When this same bacterium is
cultured under identical conditions,
except at a temperature of 25°C, the colonies will be
brick red. This difference in
color is most likely due to the (1.) type of nutrients in the
culture medium (2.) effect
of temperature on the expression of the gene for color
(3.) sterilization of the culture
medium (4.) effect of colony size on the synthesis of
color pigments
31. A cattle breeder wished to develop a strain of cattle that
would produce large quantities
of meat per animal. He chose a
bull and a cow that most nearly met his goals for breed
size. From their calves, he again
chose the male and female offspring that most nearly met
his goals. After several generations
of this style of breeding, the breeder developed a herd
of high-yield cattle. In order to maintain
this herd of high-yield cattle, which technique
should the cattle breeder use?
(1.) vegetative propagation (2.) genetic recombination
(3.) hybridization (4.) inbreeding
32. In fruit flies with the curly wing mutation, the wings will be straight
if the flies are kept at
16°C, but curly if they are kept
at 25°C. The most probable explanation for this is that
(1.) fruit flies with curly wings cannot
survive at high temperatures (2.) high
temperatures increase the rate of mutations
(3.) the environment influences wing phenotype
in these fruit flies (4.) wing
length in these fruit flies is directly proportional to temperature
33. 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
(1.) expression of inherited
traits can modify the environment
(2.) environment can influence
the development and expression of inherited traits
(3.) intelligence is a sex-linked
trait
(4.) nondisjunction occurred
in the autosomes of one twin but not the other twin
Use the diagram below and your knowledge of the living environment to answer questions 34 through 36 which follow.
| 34. Which situation would form a normal human male?
35. Which situation would form a normal human female? 36. Which situation would produce a female zygote having a nondisjunction of the 23rd chromosome pair? |
 |
| 37. 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?
(1.) 1 (2.) 2 (3.) 3 (4.) 4 |
 |
38. 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 (1.) gene
linkage (2.) dominance (3.) independent assortment
(4.) hybridization
Note that question 39 has only three choices.
39. Which statement best describes the relationship between the
number of genes and number
of chromosomes in human
skin cells? (1.) There are more genes than chromosomes in
skin cells. (2.) There
are more chromosomes than genes in skin cells. (3.) There are an
equal number of chromosomes
and genes in skin cells.
40. A woman has a gene that causes a visual disorder. To
prevent the gene from appearing in
future generations, the defective
gene would have to be repaired in the mother's
(1.) eye (2.) uterus
(3.) nervous system (4.) reproductive cells
Now hopefully some correct answers! Send any information about errors or comments to jbuckley@ekcs.neric.org
Multiple Choice Section
1. 4
2. 3
3. 1
4. 2
5. 4
6. 1
7. 2
8. 3
9. 1
10. 2
11. 2
12. 4
13. 1
14. 1
15. 1
16. 1
17. 3
18. 3
19. 4
20. 4
21. 3
22. 4
23. 3
24. 3
25. 2
26. 2
27. 4
28. 2
29. 1
30. 2
31. 4
32. 3
33. 2
34. 4
35. 1
36. 2
37. 2
38. 1
39. 1
40. 4
Free Response Section
1. List and describe at least three specific changes in chromosome structure we discussed.
2. List and describe at least three techniques used to select for better plants and animals.
Free-Response Answers
1. Some changes in chromosome structure include:
Translocation: transfer of one section of a chromosome to a nonhomologous chromosome
Addition: a portion of one chromosome is attached to another chromosome
Deletion: a portion of a chromosome is taken away from a chromosome
Inversion: a portion of a chromosome breaks off and then becomes reattached to the same chromosome in an inverted (upside down) fashion
Inbreeding-- offspring produced by artificial
selection are mated with one another to
reinforce those desirable traits
Hybridization-- crossing two individuals with
different desirable traits to produce offspring with
a combination of both desirable traits
ex.
English shorthorn cattle X Brahman cattle ->Santa Gertrudis cattle (good
beef)(heat resistance)
(good beef)
(heat resistant)
d. Mutations may be preserved by vegetative propagation. (ex. seedless oranges)
e. Recombinant DNA (genetic engineering) --- new varieties of
plants and animals can be
created by manipulating the genetic instructions
of these organisms to produce
new characteristics