Deck 27: Heredity

Question 1

An individual with two identical alleles of a gene is called which of the following?

A) Homozygous
B) Heterozygous
C) Hemizygous
D) Monogamous
E) Locus

Answer 1

A

Question 2

Which of the following describes a phenotype?

A) It situates at one or more sites on homologous chromosomes.
B) It has a unique genotype and phenotype.
C) It consists of the complete observable characteristics of an organism or group.
D) It determines each trait.
E) It is a method for calculating the number of different gametes.

Answer 2

C

Question 3

Which of the following is also called trisomy 21?

A) Klinefelter syndrome
B) Turner syndrome
C) Down syndrome
D) Cushing's syndrome
E) Cystic fibrosis

Answer 3

C

Question 4

Which of the following abnormalities is accompanied with gynecomastia, infertility, and subnormal intelligence?

A) Klinefelter syndrome
B) Turner syndrome
C) Down syndrome
D) Cushing's syndrome
E) Cystic fibrosis

Question 5

Which of the following is involved when a girl has brown eyes and blonde hair?

A) Recessive traits
B) Chromosomal abnormality
C) Genotype
D) Allelic pairs
E) Chiasma

Question 6

Crossover is the result of which of the following?

A) Exchanges of sex chromosomes
B) Recombination of genes on homologous pairs of chromosomes during meiosis
C) Alteration of two different chromosomes
D) Alteration of several heterozygous genes
E) Recombination of chromosomes on pairs of homologues

Question 7

Inheritance of height in humans may be due to which of the following?

A) Incomplete dominance
B) Polyploidy
C) Polygene inheritance
D) Polychromosomes of number 21
E) Crossing over

Question 8

Which of the following is known as the interaction of dominant and recessive alleles?

A) Crossing over
B) Autosomal recessive inheritance
C) Autosomal dominant inheritance
D) Incomplete dominance
E) Dominant-recessive inheritance

Question 9

Which of the following genetic disorders is due to a deficit of the enzyme hexosaminidase A and causes brain damage?

A) Huntington's disease
B) Tay-Sachs disease
C) Albinism
D) Phenylketonuria
E) Sickle-cell anemia

Question 10

Accumulation of phenylalanine is toxic to which of the following human organs?

A) Brain
B) Liver
C) Kidneys
D) Heart
E) Spleen

Question 11

Which of the following is an X-linked recessive disorder?

A) Phenylketonuria
B) Cystic fibrosis
C) Duchenne's muscular dystrophy
D) Astigmatism
E) Achondroplasia

Question 12

Which of the following is the most well-known example of incomplete dominance?

A) Cystic fibrosis
B) Hemophilia
C) Obesity
D) Sickle-cell anemia
E) Duchenne's muscular dystrophy

Question 13

When a color-blind man marries a woman who is heterozygous for the trait, which of the following proportions is related to their sons being color-blind?

A) 12.5%
B) 25%
C) 50%
D) 75%
E) 100%

Question 14

Which of the following statements is true about cretinism?

A) Characterized by progressive symmetric wasting of the muscles of the legs
B) The infant remains permanently stunted in growth and will be mentally disabled.
C) Requires a diet low in phenylalanine
D) Causes abnormal sweat gland function
E) There is a lack of pigment in the eyes, hair, and skin.

Question 15

Which of the following terms means "webbed fingers"?

A) Freckles
B) Achondroplasia
C) Widow's peak
D) Syndactylism
E) Dimpling

Question 16

Which of the following statements is true about autosomal-dominant conditions?

A) Require two recessive alleles
B) A heterozygote has a phenotype that is intermediate.
C) Require only one disease-causing allele for inheritance
D) They are inborn metabolic disorders.
E) Determined by genes on the sex chromosomes

Question 17

Which percentage indicates the chance that a daughter of a hemophiliac will be a carrier?

A) 12.5%
B) 25%
C) 50%
D) 60%
E) 75%

Question 18

Which of the following is the karyotype for Turner syndrome?

A) 45 Xo
B) 46 XY
C) 47 XXX
D) 47 XYY
E) 48 XYYY

Question 19

Genetic variation results from which of the following events?

A) Transmission of genes
B) Recombination of chromosomes
C) Interaction of dominant and recessive alleles
D) Crossing over and exchange of chromosomal parts
E) Replication of homologous chromosomes

Question 20

Which of the following letters is written to indicate a recessive allele?

A) T
B) TT
C) tt
D) Tt
E) t

Question 21

Which of the following diseases or conditions is caused by degeneration of basal nuclei in the brain?

A) Tay-Sachs disease
B) Marfan's syndrome
C) Huntington's disease
D) Duchenne's muscular dystrophy
E) Astigmatism

Question 22

Which of the following terms means "the all-or-none expression of an individual's genotype"?

A) Expressivity
B) Penetrance
C) Pleidotropy
D) Heterogenicity
E) Gene expression

Question 23

Which of the following controls the timing of programmed cell death during development?

A) DNA
B) tRNA
C) mRNA
D) Small RNA
E) Gene expression

Question 24

Which of the following is an example of mitochondrial inheritance?

A) Klinefelter syndrome
B) Phenylketonuria
C) Alzheimer's disease
D) Huntington's disease
E) Down syndrome

Question 25

Which of the following is an autosomal-dominant condition?

A) Freckles
B) Albinism
C) Astigmatism
D) Marfan's syndrome
E) Tongue roller

Question 26

Which of the following is not an example of polygene inheritance?

A) Cleft palate
B) Autism
C) Baldness
D) Astigmatism
E) Diabetes mellitus

Question 27

Which of the following terms describes how dramatically a phenotype manifests itself?

A) Expressivity
B) Penetrance
C) Pleidotropy
D) Polyploidy
E) Aneuploidy

Question 28

Which of the following is caused by a deletion on chromosome 15, inherited from the mother?

A) Prader-Willi syndrome
B) Marfan's syndrome
C) Down syndrome
D) Angelman's syndrome
E) Klinefelter syndrome

Question 29

Which of the following is an example of a sex-limited trait?

A) Breast size
B) Chest hair growth
C) Baldness
D) Webbed toes
E) Dwarfism

Question 30

The risk of which of the following may be increased by the chorionic villus sampling procedure?

A) Vaginal bleeding
B) Rupture of amniotic fluid
C) Septic shock
D) Finger and toe defects
E) Septicemia

Question 31

Human __________ cells contain 46, or 23 pairs of, chromosomes.

Question 32

Penetrance is the percentage of individuals with a particular genotype that show an "expected" __________.

Question 33

Chorionic villus sampling is a procedure in which villus cells are removed from the placenta and analyzed for the presence of __________ defects.

Question 34

Genes that appear on the __________ are said to be X-linked.

Question 35

Removing a sample of fluid surrounding the __________ for the purpose of studying the chromosomes is a procedure called amniocentesis.

Question 36

A person with only one allele of a gene is referred to as __________.

Question 37

__________ syndrome is characterized by hypogonadism, long legs, gynecomastia, and infertility.

Question 38

Huntington's disease is an example of a(n) __________ disorder.

Question 39

Lack of pigment in the skin, hair, and eyes is called __________.

Question 40

Phenylketonuria must be treated before the infant is three __________ old.

Question 41

Duchenne's muscular dystrophy is an X-linked __________ disorder.

Question 42

Schizophrenia and alcoholism are examples of __________ inheritance.

Question 43

Congenital hypothyroidism is also known as __________.

Question 44

Marfan syndrome is a(n) __________ dominant defect in the elastic connective tissue (fibrillin).

Question 45

The main way a recessive allele would be expressed, even when only one copy is present, would be sex-linked inheritance.

Question 46

A chromosomal aberration in which part of a chromosome is lost is called inversion.

Question 47

An example of multiple-allele inheritance is the ABO blood group.

Question 48

The sex chromosomes of a normal male are XX.

Question 49

The presence or absence of epigenetic marks may predispose cells for transformation from normal status to cancer.

Question 50

People who are heterozygous for the sickling gene (Ss) have the sickle-cell trait.

Question 51

An example of incomplete penetrance is polydactyly, in which the individual has an extra kidney.

Question 52

Turner syndrome is characterized by the absence of one Y chromosome.

Question 53

Most human traits are based on multiple alleles, or by interaction between several gene pairs.

Question 54

Cystic fibrosis is a genetic disorder of brain lipid metabolism.

Question 55

Shortened fingers and disfiguration of the hands is called brachydactyly.

Question 56

Hemophilia is caused by deficiency of either clotting factor III or X.

Question 57

Prader-Willi syndrome is a congenital metabolic condition caused by a deletion on chromosome 15, inherited from the father.

Question 58

Development of male characteristics is derived from a Y chromosome.