Download SOL 7 - TinyURL.com

Genetics test bank:
Mendel’s early work with pea plants demonstrated a significant genetic discovery. The
crossing of homozygous tall pea plants with homozygous short pea plants always resulted in
tall plants and demonstrated that tallness in pea plants is a trait that is —
A blended
B dominant _
C mutated
D recessive
Which type of characteristics can be inherited?
A Those controlled by genes _
B Those caused by accidents
C Those produced by exercise
D Those produced by diet
Which term refers to physical characteristics that are studied in genetics?
A. traits
B. offspring
C. generations
D. hybrids
What did Gregor Mendel do to study different characteristics in his genetics experiments?
A. He studied only asexual animals.
B. He studied only self-pollinating plants.
C. He cross-pollinated plants.
D. He cross-pollinated animals.
In Mendel's experiments, what proportion of the plants in the F2 generation had a trait that
had been absent in the F1 generation?
A. none
B. one fourth
C. half
D. three fourths
Factors that control traits are called
A. genes.
B. purebreds.
C. recessives.
D. parents.
The different forms of a gene are called
A. alleles.
B. factors
C. masks.
D. traits.
Scientists call an organism that has two different alleles for a trait a
A. hybrid.
B. trait.
C. purebred.
D. factor.
What does the notation TT mean to geneticists?
A. two dominant alleles
B. two recessive alleles
C. at least one dominant allele
D. one dominant and one recessive allele
What does the notation tt mean to geneticists?
A. two dominant alleles
B. two recessive alleles
C. at least one dominant allele
D. one dominant and one recessive allele
What does the notation Tt mean to geneticists?
A. two dominant alleles
B. two recessive alleles
C. at least one recessive allele
D. one dominant allele and one recessive allele
What did Mendel predict was the probability of producing a tall plant from a genetic cross
of two hybrid tall plants?
A. one in four
B. two in four
C. three in four
D. four in four
What does a Punnett square show?
A. all the possible outcomes of a genetic cross
B. only the dominant alleles in a genetic cross
C. only the recessive alleles in a genetic cross
D. all of Mendel's discoveries about genetic crosses
If a homozygous black guinea pig (BB) is crossed with a homozygous white guinea pig (bb),
what is the probability that an offspring will have black fur?
A. 25 percent
B. 50 percent
C. 75 percent
D. 100 percent
An organism's physical appearance is its
A. genotype
B. phenotype
C. codominance
D. heterozygous
An organism's genotype is its
A. genetic makeup
B. feather color
C. physical appearance
D. stem height
An organism that has two identical alleles for a trait is
A. codominant.
B. tall.
C. homozygous.
D. heterozygous.
A heterozygous organism has
A. three different alleles for a trait.
B. two identical alleles for a trait.
C. only one allele for a trait.
D. two different alleles for a trait.
What does codominance mean in genetics?
A. Both alleles are dominant.
B. Both alleles are recessive.
C. The alleles are neither dominant nor recessive.
D. Each allele is both dominant and recessive.
What are multiple alleles?
A. more than two genes that control a trait
B. three or more forms of a gene that code for a single trait
C. three or more chromosomes that determine a trait
D. more than two codominant genes in a chromosome
Which combination of sex chromosomes results in a male human being?
A. XX
B. YY
C. XY
D. either XX or YY
Sex-linked genes are genes on
A. all the chromosomes of the mother.
B. all the chromosomes of the father.
C. the X and Y chromosomes.
D. all 23 pairs of chromosomes.
Why are sex-linked traits more common in males than in females?
A. All alleles on the X chromosome are dominant.
B. All alleles on the Y chromosome are recessive.
C. A recessive allele on the X chromosome will produce the trait in a male.
D. Any allele on the Y chromosome will be codominant with the matching allele on the X
chromosome.
A carrier is a person who has
A. one recessive and one dominant allele for a trait.
B. two recessive alleles for a trait.
C. two dominant alleles for a trait.
D. more than two alleles for a trait.
How does a geneticist use pedigrees?
A. to create genetic crosses
B. to replicate identical strings of DNA
C. to prove that sex-linked traits are caused by codominant alleles
D. to trace the inheritance of traits over generations of families
What is a pedigree?
A. a chart that tracks which members of a family have a particular trait
B. a geneticist who studies the inheritance of traits in humans
C. a picture of all of the chromosomes in a cell
D. an allele passed from parent to child on a sex chromosome
Genetic disorders are caused by
A. pedigrees.
B. mutations.
C. karyotypes.
D. sickle-shaped cells.
Hemophilia is caused by a(n)
A. recessive allele on the X chromosome.
B. extra chromosome.
C. dominant allele.
D. codominant allele.
Downs Syndrome most often occurs when
A. a person inherits a recessive allele.
B. chromosomes fail to separate properly during meiosis.
C. sickle-shaped cells become stuck in blood vessels.
D. blood fails to clot properly.
What genetic disorder results in abnormally shaped blood cells?
A. hemophilia
B. Down syndrome
C. cystic fibrosis
D. sickle-cell disease
Which genetic disorder causes the body to produce unusually thick mucus in the lungs and
intestines?
A. hemophilia
B. Down syndrome
C. cystic fibrosis
D. sickle-cell disease
What procedure helps doctors diagnose a genetic disorder before a baby is born?
A. genetic engineering
B. selective breeding
C. amniocentesis
D. cloning
What is a karyotype?
A. blood from a newborn baby
B. a picture of a baby before it is born
C. a picture of the chromosomes in a cell
D. fluid that surrounds a baby before it is born
How can genetic counselors predict genetic disorders?
A. by studying karyotypes and pedigree charts
B. by taking pictures of a baby before it is born
C. by exploring new methods of genetic engineering
D. by eliminating codominant alleles in the parents
Which form of selective breeding crosses genetically different individuals in an attempt to
keep the best traits of both parents?
A. genetic engineering
B. inbreeding
C. hybridization
D. cloning
No two people have the same DNA, except for
A. crime suspects.
B. brothers.
C. sisters.
D. identical twins.
How do police use DNA fingerprinting to help solve crimes?
A. by proving that a suspect's blood type matches evidence in a crime
B. by showing that a suspect's fingerprints are at a crime scene
C. by comparing a suspect's DNA patterns with evidence from a crime scene
D. by matching phenotypes of suspects with DNA samples
Which trait-white flowers or purple flowers-is controlled by a dominant allele? Which is
controlled by a recessive allele? How do you know?
In which generation are the parents purebred? In which generation are they hybrids?
In the F1 generation, what is the genotype of the offspring? What is their phenotype?
In the F2 generation, what percent of the offspring have purple flowers? What is the genotype of
the purple-flowered offspring?
In the F2 generation, what percent of the offspring have white flowers? What are the genotypes of
the white-flowered offspring?
Suppose one of the parents of the F2 generation had been ww instead of Ww. What percent of the
offspring would have purple flowers? What percent would have white flowers?