Week 14 Flashcards
Human Genetics
Characteristics of X-Linked recessive disorders include which of the following?
A. All daughters of affected fathers are carriers
B. Boys ad girls are equally affected
C. The son of a carrier mother has a 25% chance of being affected
D. Affected fathers transmit the gene to all their sons.
A. All daughters of affected fathers are carriers
A foetus is most vulnerable to environmental teratogens during
A. Birth
B. Conception
C. The first trimester
D. The last trimester
C. The first trimester
The normal human genome contains
A. 23 chromosomes
B. 22 autosomal and 2 sex chromosomes
C. 23 pairs of autosomal chromosomes
D. 44 autosomal and 2 sex chromosomes
D. 44 autosomal and 2 sex chromosomes
Males are more likely than females to be affected by
A. X-Linked disorders
B. Autosomal dominant disorders
C. Autosomal recessive disorders
D. Chromosomal nondisjunction disorders
A. X-Linked disorders
Which of the following terms refers to the outwardly apparent physical and biochemical attributes of an individiual
A. Genotype
B. Phenotype
C. Chromatid
D. Chromosome
B. Phenotype
Genetic diseases that follow predictable patterns of inheritance usually affect
A. Chromosomal structure
B. Chromosomal number
C. Single Genes
D. Sex chromosomes
C. Single Genes
The various forms of any one gene are called
A. homologous
B. homozygous
C. heterozygous
D. alleles
D. alleles
A factor associated with risk of Downs syndrome is
A. family history of heritable diseases
B. maternal age
C. Maternal alocohol intake
D. Paternal age
B. maternal age
Duchenne muscular dystrophy (DMD) is a classic example of
A. an autosomal dominant condition
B. an autosomal recessive condition
C. an X-Linked recessive condition
D. a Y-Linked dominant condition
C. an X-Linked recessive condition
Which of the following chromosomal abnormalities has been linked with Downs syndrome
A. Translocation
B. Inversion
C. Deletion
D. Duplication
A. Translocation
If a patient has a recessive trait, which of the following is the genotype of this patient?
A. aa
B. AA
C. Aa
D. aA
A. aa
Paired chromosomes are called
A. homologous B. homozygous C. heterozygous D. autosomes E. alleles
A. homologous
Chromosomes that are not sex chromosomes are called
A. homologous B. homozygous C. heterozygous D. autosomes E. alleles
D. autosomes
The various forms of any one gene are called
A. homologous B. homozygous C. heterozygous D. autosomes E. alleles
E. alleles
If an individual carries a pair of alleles that are the same, they are ______ for the trait
A. homologous B. homozygous C. heterozygous D. autosomes E. polygenic
B. homozygous
If an individual carries two different alleles for the same trait, they are
A. homologous B. homozygous C. heterozygous D. autosomes E. polygenic
C. heterozygous
In simple inheritance, phenotypic characters are determined, or controlled, by
A. a single pair of alleles B. multiple alleles C. the action of a single gene D. regulator genes on a chromosome other than the one that has the structural genes E. the genes on the Y chromosomes
A. a single pair of alleles
In polygenic inheritance, phenotypic characters are
A. determined by a single pair of alleles
B. determined by multiple alleles
C. determined by the action of a single gene
D. always controlled by genes on the same chromosomes
E. determined by the genes on the Y chromosomes
B. determined by multiple alleles
If “A” stands for the dominant gene that prevents albinism and “a” stands for the recessive albinism trait, then an individual with the genotype of “aa” will express:
A. albinism and will be a carrier
B. albinism and will not be a carrier
C. normal pigmentation and will be a carrier
D. normal pigmentation and will not be a carrier
A. albinism and will be a carrier
An individual possessing the sex chromosome combination “XY” is genetically:
A. a male
B. a female
C. both
D. neither
A. a male
If an individual has only an X chromosome (“XO”), then that person is genetically:
A. male
B. female
C. neither male nor female
D. The condition of “XO” can never occur
A. male
The sickle cell/malaria relationship demonstrates the concept in medical genetics that “disease” genes:
A. are always codominant
B. are never dominant
C. often provide some biological advantage for a human population in certain circumstances
D. never provide a liological advantage for human populations
C. often provide some biological advantage for a human population in certain circumstances
Red-green colour blindness shows X-linked recessive inheritance. Assume “X” is normal, “X1” is recessive for the trait, and “Y” is normal. Then, an individual with the genotype “XX1” will be a:
A. normal female and a carrier
B. colour blind male
C. normal female and not a carrier
D. normal male
A. normal female and a carrier
The condition called trisomy results from a(n):
A. mistake in mitosis called nondisjunction
B. mistake in meiosis called nondisjunction
C. abnormality in a single gene
D. genetic predispostion
B. mistake in meiosis called nondisjunction
A group of symptoms called Down Syndrome results from:
A. trisomy 15
B. trisomy 19
C. trisomy 21
D. trisomy 23
C. trisomy 21
The syndrome that results from the genotype “XXY” is:
A. Turner
B. Klinefelter
C. Down
D. Parkinson
B. Klinefelter
A chart that illustrates genetic relatinships in a family over several generations is called a:
A. Punnett square
B. pedigree
C. genetic grid
D. karyotype
B. pedigree
The genetic code is transmitted to offspring in discrete, independent units that are called:
A. chromosomes
B. genes
C. gametes
D. nucleosomes
B. genes
He entire collection of genetic material in each typical cell of the human body is called:
A. diploid
B. haploid
C. nucleosomes
D. genome
D. genome
If a karyotype found an X chromsome, a Y chromosome, and three 21st chromosomes, it would indicate a:
A. female with down syndrome
B. female with Turner syndrome
C. male with Klinefelter syndrome
D. male with down syndrome
D. male with down syndrome
