Section 1 Flashcards
How many chromosomes are shown in a normal human karotype? A.2 B.23 C.44 D.46
D.46
Which of the following are shown in a karotype? A. Homologous chromosomes B.Sex Chromosomes C.autosomes D.all of the above
D. All of the above
Which of the following can be observed in a Karotype? A. A change in a DNA base B. an extra chromosome C.genes D.alleles
B. an extra chromosome
In humans, a male only has.... A. One X chromosome only B. two X chromosomes C. One X chromosome and one Y chromosome D. Two Y chromosome
C.One X chromosome and one Y chromosome
Human females produce egg cells that have.... A. One X chromosome B. Two X chromosomes C. One X or one Y chromosome D. One X and one Y chromosome
A. One X chromosome
What is the probability that a human offspring will be female? A.10% B.25% C.50% D.75%
C.50%
What percent of human sperm cells carry an X chromosome? A.0% B.25% C.50% D.100%
C.50%
A human female inherits
a. one copy of every gene located on each of the X chromosomes.
b. twice as many sex chromosomes as a human male inherits.
c. one copy of every gene located on the Y chromosome.
d. all of the same genes that a human male inherits.
a.one copy of every gene located on each of the X chromosomes.
In a pedigree, a circle represents a(an)
a. male
b. female.
c. child.
d. adult.
b.female.
A pedigree can be used to
a. determine whether a trait is inherited.
b. show how a trait is passed from one generation to the next.
c. determine whether an allele is dominant or recessive.
d. all of the above
d. all of the above
Which of the following would you be least likely to see in a pedigree?
a. All of the symbols are unshaded.
b. All of the symbols are shaded.
c. All of the symbols are squares.
d. About half of the symbols are circles.
c. All of the symbols are squares.
Which of the following is caused by a dominant allele?
a. Huntington’s disease
b. PKU
c. Tay-Sachs disease
d. none of the above
a.Huntington’s disease
Which of the following is determined by multiple alleles?
a. Rh blood group
b. ABO blood group
c. PKU
d. Huntington’s disease
b.ABO blood group
A person who has PKU
a. inherited the recessive allele for the trait from one parent.
b. inherited the recessive allele for the trait from both parents.
c. is heterozygous for the trait.
d. will not pass the allele for the trait to his or her offspring.
b.inherited the recessive allele for the trait from both parents.
Which of the following genotypes result in the same phenotype?
a. IAIA and IAIB
b. IBIB and IBi
c. IBIB and IAIB
d. IBi and ii
b.IBIB and IBi
If a man with blood type A and a woman with blood type B produce an offspring, what might be the offspring’s blood type?
a. AB or O
b. A, B, or O
c. A, B, AB, or O
d. AB only
c.A, B, AB, or O
Which of the following statements is NOT true?
a. A person with Huntington’s disease might not pass the allele for the disease to his or her offspring.
b. A person with Huntington’s disease might be homozygous for the disease.
c. Huntington’s disease is caused by a recessive allele.
d. A person who inherits one allele for Huntington’s disease will develop the disease.
c.Huntington’s disease is caused by a recessive allele.
Sickle cell disease is caused by a
a. change in one DNA base.
b. change in the size of a chromosome.
c. change in two genes.
d. change in the number of chromosomes in a cell.
a.change in one DNA base.
In cystic fibrosis, a change in a single gene causes the protein called CFTR to
a. become less soluble.
b. fold improperly.
c. destroy the cell membrane.
d. transport sodium ions instead of chloride ions.
b.fold improperly.
Compared with normal hemoglobin, the hemoglobin of a person with sickle cell disease
a. is longer.
b. is shorter.
c. has a different sequence of amino acids.
d. is wider.
c.has a different sequence of amino acids.
Which of the following does NOT lead to cystic fibrosis?
a. missing codon in mRNA
b. shorter CFTR polypeptide chain
c. point mutation
d. absence of CFTR in cell membrane
c.point mutation
People who are heterozygous for sickle cell disease are generally healthy because
a. they are resistant to malaria.
b. they usually have some normal hemoglobin in their red blood cells.
c. their abnormal hemoglobin usually doesn’t cause their red blood cells to become sickle shaped.
d. they do not produce abnormal hemoglobin.
b.they usually have some normal hemoglobin in their red blood cells.
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
b.three or more forms of a gene that code for a single trait
Why does height in humans have such a wide variety of phenotypes?
a. Height is controlled by at least four genes.
b. The gene for height has only two alleles.
c. Height is controlled by sex-linked genes.
d. Height is controlled by a recessive allele.
a.Height is controlled by at least four genes.
What controls variations in skin color among humans? A.a person’s diet B.many genes C.multiple alleles of a single gene D.two alleles of a single gene
B.many genes
Which of these human traits is altered by variations in environment?
a. hairline
b. height
c. smile dimples
d. blood type
b.height
What factors can affect a person’s height?
a. genes only
b. both genes and environmental factors
c. a person’s blood type
d. a person’s karyotype
b.both genes and environmental factors
Which combination of sex chromosomes results in a male human being?
a. XX
b. YY
c. XY
d. either XX or YY
c.XY
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 in humans
d.to trace the inheritance of traits in humans
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
a.a chart that tracks which members of a family have a particular trait