The appearance of freckles is considered:
a the genome.
b
the phenotype.
c the genotype.
d sex linked.
B. the phenotype
In females, one of the X chromosomes is inactivated by:
a
environmental factors.
b enzymes coded for by mitochondrial DNA.
c epigenetic markers.
d the number of dominant genes
present on each X chromosome
C. epigenetic markers
Males tend to inherit more sex-linked conditions because:
a.
they have two Y chromosomes.
b. there is no corresponding
alleles on their X chromosomes.
c. they have more chromosomes
than females.
d. there is no corresponding allele on their Y
chromosomes.
e. they have two X chromosomes.
D. there is no corresponding allele on their Y chromosomes.
A change in the genetic structure of a gene is called:
a
mutation.
b deletion.
c duplication.
d
translocation.
e inversion.
A. mutation
Extrachromosomal inheritance involves genes passed on by the
mother's:
a mitochondria.
b Golgi bodies.
c smooth
ER.
d chromosomes.
e cytoplasm.
A. mitochondria
The most common form of fetal testing is:
a somatic
visualization.
b chorionic villi sampling.
c teratogenic
sampling.
d gene therapy.
e amniocentesis.
E. amniocentesis
The expression of genes is called the:
a genotype.
b
autotype.
c phenotype.
d pedigree.
e genome.
C. phenotype
Traits that display continuous phenotypic variation are usually
determined by this form of inheritance.
a Dominant-recessive
inheritance
b Incomplete dominance
c Sex-linked
inheritance
d Polygenic inheritance
e Multiple-allele inheritance
D. polygenic inheritance
What is the probability of having a child with a recessive trait if
both parents are heterozygous for the trait?
a 50%
b 25%
c 100%
d 10%
e 75%
b. 25%
Heterozygous individuals that can pass on recessive, abnormal
conditions are referred to as:
a zygotic.
b phenotypically
challenged.
c deleterious donators.
d carriers.
e
recessively compromised.
d. carriers
A type of treatment useful in correcting single-gene disorders is:
a genetic dysplasia.
b somatic recombination.
c gene
therapy.
d amniocentesis.
e chorionic villi sampling.
c. gene therapy
Genes that are located on the same chromosome are said to be:
a
dominant.
b crossed.
c linked.
d syncopated.
e tied.
C. linked
In the human blood type AB, the alleles are:
a codominant.
b dominant.
c sex-linked.
d polygenic.
a.codominant
Which of the following disorders is NOT inherited as simple recessive
traits?
a Cystic fibrosis
b Albinism
c Tay-Sachs
disease
d Down syndrome
e Schizophrenia
d. down syndrome
Which of the following is NOT a source of genetic variation?
A)
independent assortment of chromosomes
B) crossover of
homologs
C) age of either or both parents
D) random
fertilization of eggs by sperm
C
True or False
Hemophilia is an X-linked condition caused by a recessive gene.
T
True or False
Most genetic disorders are inherited through dominant genes.
False
The gene responsible for the condition known as sickle-cell anemia demonstrates ___.
incomplete dominance
True or False
When two genes are on the same chromosome, they are considered linked.
True
Some segments of the Y chromosome have no counterpart on the X chromosome. T/F
True