Deck 3: Changes in Chromosome Number

Question 1

Meiosis in females

A) leads to the production of sperm.
B) only produces polar bodies.
C) has already completed by the time of her birth.
D) only completes if an oocyte is fertilized.
E) never completes.

Answer 1

D

Question 2

At the end of meiosis,the number of chromosomes in each daughter cell is _____ the number of chromosomes that were present in the original parent cell.

A) the same as
B) double
C) half
D) triple
E) four times

Answer 2

C

Question 3

Amniocentesis

A) involves removal of fluid and cells from around the fetus.
B) is usually used to determine if a female is pregnant.
C) is performed at or around the 12th week of pregnancy
D) involves a risk of about 1% for miscarriage
E) has a high risk for the mother's health.

Answer 3

A

Question 4

What chromosomal change(s)can lead to birth defects?

A) additional copies of chromosomes
B) aneuploidy
C) duplications of segments of chromosomes
D) deletions of segments of chromosomes
E) All of these can lead to birth defects.

Question 5

Under what circumstance(s)is it recommended that a woman undergo amniocentesis?

A) The woman will be 25 years of age or older at the time of birth.
B) The woman has not had a previous child with a chromosomal aberration.
C) Either parent has a known structurally abnormal chromosome.
D) The father will be 35 years of age or older at the time of the birth.
E) The parents want to have a karyotype of their child.

Question 6

If a normal diploid cell from a certain animal species contains 36 chromosomes,an oocyte from a female of this species contains ____ chromosomes.

A) 9
B) 12
C) 18
D) 36
E) 72

Question 7

A human cell that is polyploid might have _____ chromosomes.

A) 45
B) 46
C) 47
D) 92
E) 23

Question 8

All of the following trisomies can still lead to live births EXCEPT

A) Trisomy 1
B) Trisomy 13
C) Trisomy 18
D) Trisomy 21
E) Trisomy 8

Question 9

What is considered the main risk factor for having a child with Down syndrome?

A) maternal age
B) paternal age
C) exposure to radiation
D) exposure to cancer-causing chemicals
E) the combined age of the parents

Question 10

Sperm and oocytes are

A) triploid.
B) aneuploid.
C) haploid.
D) diploid.
E) polyploid.

Question 11

Which of the following chromosomes is the smallest in size?

A) chromosome 22
B) chromosome 1
C) X chromosome
D) chromosome 12
E) chromosome 2

Question 12

Under what circumstances might a couple consult with a genetic counselor?

A) If the woman will be over 35 years of age at the time of birth
B) Couples who are first cousins or other blood relatives
C) Couples who come from ethnic groups in which certain types of genetic defects are more common
D) Couples who have already had a child with a genetic disorder
E) All of these are possible reasons to consult with a genetic counselor.

Question 13

The end result of meiosis is

A) four haploid cells.
B) two diploid cells.
C) two haploid cells and two diploid cells.
D) four diploid cells.
E) two haploid cells.

Question 14

Individuals with Jacobs syndrome are

A) 47, XYY.
B) 45, X.
C) 47, XXY.
D) 47, +13
E) 47, +21

Question 15

Nondisjunction refers to

A) the failure of cells to separate properly during mitosis.
B) the failure of chromosomes to separate properly during meiosis.
C) a chromosomal mutation.
D) the failure of chromosomes to replicate.
E) the inability to produce sperm.

Question 16

This test requires growing the isolated cells for about a week and can indicate prenatal chromosomal abnormalities.

A) amniocentesis
B) chorionic villus sampling (CVS)
C) pregnancy testing that detects hormone levels
D) analysis of free fetal DNA.
E) analysis of the father's DNA.

Question 17

What kinds of chromosomal defects invariably result in miscarriage in early pregnancy?

A) all trisomies involving autosomes
B) all monosomies involving autosomes
C) all monosomies involving the sex chromosomes
D) all trisomies involving chromosome 21
E) all trisomies involving the sex chromosomes

Question 18

What is the advantage of performing CVS over amniocentesis?

A) CVS can be done earlier in the pregnancy.
B) With CVS, there is no risk of miscarriage.
C) CVS allows chromosomal analysis; amniocentesis does not.
D) There is no advantage to performing CVS over amniocentesis.
E) CVS can be performed on the father; amniocentesis must be performed on the mother.

Question 19

The most common cause of both trisomy and monosomy is

A) exposure to radiation.
B) carcinogenic agents.
C) smoking.
D) nondisjunction.
E) None of these are the most common cause of trisomy and monosomy.

Question 20

An individual with only one X chromosome and no other sex chromosome

A) is female.
B) is male.
C) is never born.
D) never develops completely.
E) has Jacobs syndrome.

Question 21

A karyotype

A) will change during the course of an individual's lifetime.
B) does not provide any information on the sex of a fetus.
C) is a microscope slide containing a spread of chromosomes from a single cell.
D) shows the chromosomes from the mother separated from those from the father.
E) can be used to determine whether an individual is aneuploid or not.

Question 22

Structural changes in chromosomes never lead to genetic defects.

Question 23

Aneuploidy is a major cause of early miscarriages.

Question 24

To produce an individual with Kleinfelter syndrome (47,XXY),

A) a nondisjunction event must have occurred during spermatogenesis.
B) more than one sperm must have been involved in fertilization.
C) a nondisjunction event must have occurred during oogenesis.
D) this must have been caused by uniparental disomy.
E) a nondisjunction event could have occurred during spermatogenesis or oogenesis.

Question 25

To produce an individual with Jacobs syndrome (47,XYY),

A) a nondisjunction event must have occurred during spermatogenesis.
B) more than one sperm must have been involved in fertilization.
C) a nondisjunction event must have occurred during oogenesis.
D) this must have been caused by uniparental disomy.
E) a nondisjunction event could have occurred during spermatogenesis or oogenesis.

Question 26

Individuals with Klinefelter syndrome have XXY sex chromosomes.

Question 27

The condition in which there is only a single copy of an autosome in a diploid cell is known as

A) monosomy.
B) trisomy.
C) diploidy.
D) polyploidy.
E) haploidy.

Question 28

Different versions of genes are called

A) homologues.
B) alleles.
C) autosomes.
D) sister chromatids.
E) centromeres.

Question 29

Telomeres may play a role in aging.

Question 30

Meiosis involves a reduction in the number of chromosomes.

Question 31

One type of aneuploidy is Down syndrome.

Question 32

Nondisjunction events can lead to aneuploidy.

Question 33

Uniparental disomy

A) describes a condition in which an individual has an abnormal number of chromosomes.
B) never causes any genetic problems.
C) has been determined to be involved in Angelman syndrome.
D) can be the cause of Turner syndrome.
E) can lead to autosomal monosomy.

Question 34

Monosomy involving an autosomal chromosome is never fatal.

Question 35

Autosomal trisomies

A) usually do not cause any abnormalities.
B) cannot occur.
C) never lead to live births.
D) usually lead to miscarriages.
E) are usually due to chromosomal duplications.

Question 36

To produce an individual with Down syndrome (47,+21),

A) a nondisjunction event must have occurred during spermatogenesis.
B) more than one sperm must have been involved in fertilization.
C) a nondisjunction event must have occurred during oogenesis.
D) this must have been caused by uniparental disomy.
E) a nondisjunction event could have occurred during spermatogenesis or oogenesis.

Question 37

To produce an individual with Turner syndrome (45,X),

A) a nondisjunction event must have occurred during spermatogenesis.
B) more than one sperm must have been involved in fertilization.
C) a nondisjunction event must have occurred during oogenesis.
D) this must have been caused by uniparental disomy.
E) a nondisjunction event could have occurred during spermatogenesis or oogenesis.

Question 38

Mothers who are over the age of 35 have a higher likelihood of having a child with genetic defects than do younger mothers.

Question 39

Polar bodies form

A) only if fertilization occurs.
B) due to unequal cytoplasmic division during oogenesis.
C) only when a nondisjunction event has occurred.
D) due to unequal cytoplasmic division during spermatogenesis.
E) after a woman has reached menopause.

Question 40

Homologous chromosomes

A) carry different genes at different positions.
B) carry the same genes at different positions.
C) carry some of the same genes but also some different genes.
D) are both inherited from the same parent.
E) carry the same genes at the same positions.

Question 41

MATCHING
Match the correct syndromes with the genetic abnormality.
a.Trisomy 21
b.XXY
c.XO
d.47, +13
e.Trisomy 18
f.47, XYY
Turner syndrome

Question 42

The p arm.

Question 43

What is the purpose of genetic counseling? What kinds of information must a genetic counselor take into account in order to assess patient risk for genetic disorders?

Question 44

Identify and describe two medical tests that can be used to detect chromosomal abnormalities in a fetus.What are advantages and disadvantages of each?

Question 45

MATCHING
Match the correct syndromes with the genetic abnormality.
a.Trisomy 21
b.XXY
c.XO
d.47, +13
e.Trisomy 18
f.47, XYY
Jacobs syndrome

Question 46

MATCHING
Match the correct syndromes with the genetic abnormality.
a.Trisomy 21
b.XXY
c.XO
d.47, +13
e.Trisomy 18
f.47, XYY
Edwards syndrome

Question 47

The location of this can vary depending on the chromosome.

Question 48

These shorten after each cell division.

Question 49

Describe chromosomal nondisjunction? What are the consequences of nondisjunction in meiosis?

Question 50

The q arm.

Question 51

Match the appropriate term with the description or term.
a.Zygote
b.Involves gain or loss of a chromosome
c.Sperm cell
d.Extra copies of all the chromosomes
Haploid

Question 52

Sister chromatids.

Question 53

Match the appropriate term with the description or term.
a.Zygote
b.Involves gain or loss of a chromosome
c.Sperm cell
d.Extra copies of all the chromosomes
Polyploid

Question 54

Maternal age is the only known risk factor for aneuploidy.What are possible reasons for the increased risk associated with increase maternal age?

Question 55

MATCHING
Match the correct syndromes with the genetic abnormality.
a.Trisomy 21
b.XXY
c.XO
d.47, +13
e.Trisomy 18
f.47, XYY
Down syndrome

Question 56

MATCHING
Match the correct syndromes with the genetic abnormality.
a.Trisomy 21
b.XXY
c.XO
d.47, +13
e.Trisomy 18
f.47, XYY
Klinefelter syndrome

Question 57

Match the appropriate term with the description or term.
a.Zygote
b.Involves gain or loss of a chromosome
c.Sperm cell
d.Extra copies of all the chromosomes
Aneuploid

Question 58

Turner syndrome involves monosomy of the Y chromosome.

Question 59

MATCHING
Match the correct syndromes with the genetic abnormality.
a.Trisomy 21
b.XXY
c.XO
d.47, +13
e.Trisomy 18
f.47, XYY
Patau syndrome

Question 60

Match the appropriate term with the description or term.
a.Zygote
b.Involves gain or loss of a chromosome
c.Sperm cell
d.Extra copies of all the chromosomes
Diploid

Question 61

Describe three major structural changes in chromosomes that can lead to genetic abnormalities?

Question 62

In most cases of Down syndrome,there is no family inheritance pattern.Individuals with Down syndrome are born to mothers even when there has been no family history of Down syndrome.However,in rare cases,there is a family inheritance pattern.Describe the cause of this rare form of Down syndrome and explain why this form shows a family inheritance pattern.