Human Heredity Principles And Issues 11th Edition by Michael Cummings – Test Bank A+

$35.00

Human Heredity Principles And Issues 11th Edition by Michael Cummings – Test Bank A+

Name: Human Heredity Principles And Issues 11th Edition by Michael Cummings – Test Bank A+
SKU: Human Heredity Principles And Issues 11th Edition by Michael Cummings – Test Bank A+
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$35.00

SKU: Human Heredity Principles And Issues 11th Edition by Michael Cummings – Test Bank A+

Description

. Trisomy 21 is the only autosomal trisomy that allows survival into adulthood.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-2 – Explain how the chromosomal abnormalities of triploidy and tetraploidy occur, and list the characteristics of each genetic condition.

2. Turner syndrome is not associated with intellectual disability.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-7 Sex Chromosome Aneuploidy
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-7-1 – Summarize the characteristics of sex chromosome aneuploidies observed in humans, including Turner syndrome, Klinefelter syndrome, and XYY syndrome.

3. Amniocentesis is not performed on mothers over the age of thirty-five.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-2 – Summarize the procedures of amniocentesis, chorionic villus sampling (CVS), and fetal DNA or free fetal DNA (ffDNA), and compare and contrast the advantages of each.

4. Using fetal DNA from the mother’s blood for prenatal testing is a noninvasive procedure.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-4 – Describe the procedure of prenatal testing using fetal DNA or free fetal DNA (ffDNA), identify its uses, and list its advantage over amniocentesis and CVS.

5. Submetacentric describes a chromosome whose telomeres are attached to the centromeres.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-2 The Human Chromosome Set
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-2-1 – Identify the physical characteristics of a human chromosome and of a chromosome set.

6. Down syndrome can be caused by either trisomy 21 or a Robertsonian translocation.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-5 Variations in Chromosome Number 6-8 Structural Changes Within and Between Chromosomes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-1 – Outline the common chromosomal abnormalities observed in humans. HUHE.CUMM.16.6-8-3 – Describe the two major types of translocations and explain the relationship of Robertsonian translocations to Down syndrome.

7. Chromosomes are usually studied and photographed while they are in anaphase of mitosis.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-3 Making a Karyotype
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-3-1 – Define the term karyotype and describe the process of karyotype preparation.

8. The risk of having a child with Down syndrome due to a chromosomal translocation is independent of maternal age.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-8 Structural Changes Within and Between Chromosomes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-8-3 – Describe the two major types of translocations and explain the relationship of Robertsonian translocations to Down syndrome.

9. Leukemia is often associated with chromosomal translocations.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-9 What Are Some Consequences of Aneuploidy?
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-9-2 – Outline three main consequences of aneuploidy in humans.

10. Viral infections are not considered a risk factor for autosomal trisomy because a virus cannot affect human chromosome arrangement.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-6 What Are the Risks for Autosomal Trisomy?
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-6-1 – Describe the genetic and environmental factors that may cause autosomal trisomy.

Multiple Choice

11. Polyploidy is characterized by ____.

	a.	the failure of homologous chromosomes to separate properly during meiosis
	b.	a condition in which one chromosome is present in three copies
	c.	a condition in which one member of a chromosomal pair is missing
	d.	a chromosomal number that is not an exact multiple of the haploid set
	e.	a chromosomal number that is a multiple of the normal haploid chromosomal set

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-1 – Outline the common chromosomal abnormalities observed in humans.

12. The most common type of polyploidy in humans is ____.

	a.	trisomy
	b.	monosomy
	c.	triploidy
	d.	tetraploidy
	e.	haploidy

ANSWER:	c
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-1 – Outline the common chromosomal abnormalities observed in humans.

13. The risk for Down syndrome increases ____.

	a.	when the mother is over thirty-five years old
	b.	when the father is over thirty-five years old
	c.	when the father is over fifty years old
	d.	for dizygotic twins
	e.	for monozygotic twins

ANSWER:	a
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-6 What Are the Risks for Autosomal Trisomy?
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-6-2 – Explain why maternal age is the leading risk factor for trisomy.

14. If nondisjunction occurs during meiosis I, ____.

	a.	two gametes will be normal and two will be missing one chromosome
	b.	two gametes will be normal and two will have one extra chromosome
	c.	three gametes will be normal and one will have two extra chromosomes
	d.	all gametes will be normal
	e.	all gametes will be abnormal

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-2 – Explain how the chromosomal abnormalities of triploidy and tetraploidy occur, and list the characteristics of each genetic condition.

15. Studies of sex chromosome aneuploidy reveal that ____ necessary for survival.

	a.	the X chromosome is not
	b.	the Y chromosome is not
	c.	two copies of the X chromosome are
	d.	two copies of the Y chromosome are
	e.	at least one copy of both the X and the Y chromosome is

ANSWER:	b
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-7 Sex Chromosome Aneuploidy
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-7-2 – Discuss the conclusions that can be drawn from the study of sex chromosome disorders.

16. One important difference between amniocentesis and chorionic villus sampling is that ____.

	a.	chorionic villus sampling is more routine
	b.	amniocentesis can diagnose chromosome disorders, while chorionic villus sampling cannot
	c.	chorionic villus sampling can be done earlier in the pregnancy than amniocentesis
	d.	maternal risks are higher with chorionic villus sampling
	e.	the risk of miscarriage is higher with amniocentesis than with chorionic villus sampling

ANSWER:	c
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-3 – Describe the procedure of chorionic villus sampling (CVS), identify its uses, and list its advantages over amniocentesis.

17. About ____ percent of children with Down syndrome are severely intellectually disabled.

	a.	five
	b.	ten
	c.	twenty-five
	d.	thirty
	e.	forty

ANSWER:	b
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-1 Facing a Life-Changing Decision
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-1-1 – Identify the most common chromosomal disorder in humans and outline the range of disabilities that could occur in an affected child.

18. Spindle fibers attach to the ____ of a chromosome during cell division.

	a.	centromere
	b.	telomere
	c.	cell membrane
	d.	short arms
	e.	gametes

ANSWER:	a
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-2 The Human Chromosome Set
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-2-1 – Identify the physical characteristics of a human chromosome and of a chromosome set.

19. When constructing a karyotype, the chromosome images are arranged in pairs according to ____________________ and ____________________.

	a.	size; telomere location
	b.	size; centromere location
	c.	banding pattern; centromere location
	d.	banding pattern; telomere location
	e.	size; banding pattern

ANSWER:	b
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-3 Making a Karyotype
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-3-1 – Define the term karyotype and describe the process of karyotype preparation.

20. The letters G, Q, R, and C, used to describe the appearance of chromosomes, refer to the ____.

	a.	position of the bands
	b.	staining procedure used to reveal the bands
	c.	number of arms per chromosome
	d.	number of centromeres per chromosome
	e.	position of the centromeres

ANSWER:	b
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-1 – List the cell types used to produce a karyotype, and describe the techniques used in karyotype analysis.

21. Most triploid zygotes probably arise from ____.

	a.	incomplete meiosis I
	b.	incomplete meiosis II
	c.	incomplete mitosis
	d.	nondisjunction
	e.	dispermy

ANSWER:	e
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-1 – Outline the common chromosomal abnormalities observed in humans.

22. More than ____ percent of couples decide to terminate a Down syndrome pregnancy.

	a.	ten
	b.	thirty
	c.	fifty
	d.	seventy
	e.	ninety

ANSWER:	e
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-1 Facing a Life-Changing Decision
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-1-1 – Identify the most common chromosomal disorder in humans and outline the range of disabilities that could occur in an affected child.

23. Regions at the ends of chromosomes that prevent chromosomes from sticking to each other are called ____.

	a.	satellites
	b.	telomeres
	c.	centromeres
	d.	q zones
	e.	p zones

ANSWER:	b
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-2 The Human Chromosome Set
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-2-1 – Identify the physical characteristics of a human chromosome and of a chromosome set.

24. A deletion in the short arm of chromosome 5 is associated with ____ syndrome, which causes intellectual disability, defects in facial development, and an abnormal larynx.

	a.	Down
	b.	Klinefelter
	c.	Turner
	d.	cri du chat
	e.	XYY

ANSWER:	d
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-8 Structural Changes Within and Between Chromosomes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-8-2 – Explain the cause of cri du chat syndrome and list its symptoms.

25. One type of polyploidy is ____.

	a.	aneuploidy
	b.	trisomy
	c.	triploidy
	d.	deletion
	e.	translocation

ANSWER:	c
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-1 – Outline the common chromosomal abnormalities observed in humans.

26. About ____ percent of all newborns are affected with an abnormal karyotype.

	a.	0.001
	b.	0.01
	c.	0.05
	d.	0.5
	e.	1.0

ANSWER:	c
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-9 What Are Some Consequences of Aneuploidy?
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-9-1 – Report on the data supporting the concept that aneuploidies are a major cause of miscarriage.

27. Autism, Alzheimer disease, Parkinson’s disease, and schizophrenia are all associated with ____.

	a.	copy number variants
	b.	fragile sites
	c.	inversions
	d.	deletions
	e.	translocations

ANSWER:	a
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-10 Other Forms of Chromosome Changes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-10-1 – Describe the chromosomal changes that are not detectable by karyotype analysis, including uniparental disomy (UPD), copy number variants (CNVs), and fragile sites.

28. The major physical symptom associated with Klinefelter syndrome is ____.

	a.	facial deformation
	b.	fertility problems
	c.	short stature
	d.	intellectual disability
	e.	heart abnormalities

ANSWER:	b
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-7 Sex Chromosome Aneuploidy
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-7-1 – Summarize the characteristics of sex chromosome aneuploidies observed in humans, including Turner syndrome, Klinefelter syndrome, and XYY syndrome.

29. Deletion of an entire autosome ____.

	a.	causes XYY syndrome
	b.	causes Down syndrome
	c.	causes no physical symptoms
	d.	is lethal
	e.	is called polyploidy

ANSWER:	d
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-8 Structural Changes Within and Between Chromosomes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-8-1 – Diagram the structural changes that can occur within and between chromosomes, including duplications, translocations, deletions, and inversions.

30. In a(n) ____ translocation, two nonhomologous chromosomes exchange parts and no genetic information is gained or lost from the cell in the exchange.

	a.	cri du chat
	b.	XXY
	c.	copy number
	d.	Robertsonian
	e.	reciprocal

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-8 Structural Changes Within and Between Chromosomes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-8-3 – Describe the two major types of translocations and explain the relationship of Robertsonian translocations to Down syndrome.

Completion

31. A chromosome that has a centrally-placed centromere is called ____________________.

ANSWER:	metacentric
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-2 The Human Chromosome Set
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-2-1 – Identify the physical characteristics of a human chromosome and of a chromosome set.

32. The karyotype designation for an infant with a deletion in the short arm of chromosome 5 (cri du chat syndrome) is ____________________

ANSWER:	46, del(5p)
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	6-4 Analyzing Karyotypes 6-8 Structural Changes Within and Between Chromosomes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-1 – List the cell types used to produce a karyotype, and describe the techniques used in karyotype analysis. HUHE.CUMM.16.6-8-2 – Explain the cause of cri du chat syndrome and list its symptoms.

33. Researchers have suggested that all live-born infants with Turner syndrome are actually ____________________, with both 46,XX and 45,X cells present in their bodies.

ANSWER:	mosaics
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-7 Sex Chromosome Aneuploidy
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-7-1 – Summarize the characteristics of sex chromosome aneuploidies observed in humans, including Turner syndrome, Klinefelter syndrome, and XYY syndrome.

34. The karyotype designation for a female with X chromosome trisomy is ____________________.

ANSWER:	47, XXX
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-1 – List the cell types used to produce a karyotype, and describe the techniques used in karyotype analysis.

35. There are ____________________ chromosomes in a human tetraploid cell.

ANSWER:

ninety-two

DIFFICULTY:

Bloom’s: Understand

REFERENCES:

6-5 Variations in Chromosome Number

36. The long arm of a chromosome is called the ____________________ arm.

ANSWER:	q
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-2 The Human Chromosome Set
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-2-1 – Identify the physical characteristics of a human chromosome and of a chromosome set.

37. One possible explanation for why ____________________ is a primary risk factor for autosomal trisomy is that oocytes remain in meiosis I until ovulation, which could take place many years after birth, making them more susceptible to damage.

ANSWER:	maternal age age age of the mother
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-6 What Are the Risks for Autosomal Trisomy?
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-6-2 – Explain why maternal age is the leading risk factor for trisomy.

38. One technique for chromosome analysis is called ____________________, which uses chromosome-specific DNA sequences attached to fluorescent dyes to target specific chromosomal regions.

ANSWER:	chromosome painting
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-1 – List the cell types used to produce a karyotype, and describe the techniques used in karyotype analysis.

39. Approximately 40% of all children with Down syndrome have congenital ____________________ defects.

ANSWER:	heart
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-3 – Describe the progression and characteristics of aneuploidy, and differentiate among monosomy, trisomy 13, trisomy 18, and trisomy 21.

40. Fragile sites appear as ____________________ or ____________________ at specific sites on a chromosome.

ANSWER:

gaps; breaks

breaks; gaps

DIFFICULTY:

Bloom’s: Understand

REFERENCES:

6-10 Other Forms of Chromosome Changes

41. A chromosome whose centromere is placed very close to, but not at, one end is called a(n) ____________________ chromosome.

ANSWER:	acrocentric
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-2 The Human Chromosome Set
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-2-1 – Identify the physical characteristics of a human chromosome and of a chromosome set.

42. Amniocentesis collects cells from the fluid surrounding the fetus in order to prepare a(n) ____________________.

ANSWER:	karyotype
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-2 – Summarize the procedures of amniocentesis, chorionic villus sampling (CVS), and fetal DNA or free fetal DNA (ffDNA), and compare and contrast the advantages of each.

43. Part of a chromosome moves to another, nonhomologous chromosome during ____________________.

ANSWER:	translocation
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-8 Structural Changes Within and Between Chromosomes

44. Changes in the number of copies of chromosomal DNA segments and the genes they contain are called ____________________.

ANSWER:

copy number variants

CNVs

CNV

DIFFICULTY:

Bloom’s: Remember

REFERENCES:

6-10 Other Forms of Chromosome Changes

45. Karyotypes prepared from chorionic villus cells can be used to identify many ____________________ abnormalities.

ANSWER:	chromosomal chromosome
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-1 – List the cell types used to produce a karyotype, and describe the techniques used in karyotype analysis. HUHE.CUMM.16.6-4-3 – Describe the procedure of chorionic villus sampling (CVS), identify its uses, and list its advantages over amniocentesis.

46. Early investigators associated the tendency to violent criminal behavior with the ____________________ karyotype, but there is no evidence of a direct link between the two.

ANSWER:	XYY XYY syndrome 47, XYY
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	6-7 Sex Chromosome Aneuploidy
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-7-1 – Summarize the characteristics of sex chromosome aneuploidies observed in humans, including Turner syndrome, Klinefelter syndrome, and XYY syndrome.

47. A condition in which both copies of a chromosome are inherited from one parent is called ____________________.

ANSWER:

uniparental disomy

UPD

DIFFICULTY:

Bloom’s: Remember

REFERENCES:

6-10 Other Forms of Chromosome Changes

48. The FRAX A site near the tip of the long arm of the X chromosome is associated with a form of intellectual disability known as Martin-Bell syndrome, or ____________________.

ANSWER:

fragile-X syndrome

fragile-X

DIFFICULTY:

Bloom’s: Remember

REFERENCES:

6-10 Other Forms of Chromosome Changes

49. Almost all chromosomally abnormal embryos and fetuses are ____________________ as pregnancy progresses.

ANSWER:	eliminated miscarried spontaneously aborted
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-9 What Are Some Consequences of Aneuploidy?
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-9-1 – Report on the data supporting the concept that aneuploidies are a major cause of miscarriage.

50. Free fetal DNA (ffDNA) originates from the breakdown of fetal cells and their nuclei in the ____________________.

ANSWER:	amniotic fluid
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-4 – Describe the procedure of prenatal testing using fetal DNA or free fetal DNA (ffDNA), identify its uses, and list its advantage over amniocentesis and CVS.

Essay

51. Define aneuploidy and describe the sex chromosome aneuploidies involved in Turner syndrome, Klinefelter syndrome, and XYY syndrome; list characteristics of each disorder.

ANSWER:	Changes in chromosome number that involve less than a whole chromosome set are called aneuploidy. In its simplest form, aneuploidy involves the gain or loss of a single chromosome. Loss of a single chromosome is known as monosomy, and the gain of a single chromosome is known as trisomy. Females with Turner syndrome have monosomy of the X chromosome and are typically short, wide-chested, with rudimentary ovaries and puffiness of the hands and feet. They may have an aortic constriction, but there is no intellectual disability associated with this condition. Most males with Klinefelter syndrome have an extra X chromosome (XXY). They have fertility problems but few other symptoms. Males carrying two Y chromosomes have XYY syndrome. Most are above average in height, have personality disorders, and are of subnormal intelligence.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number 6-7 Sex Chromosome Aneuploidy
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-3 – Describe the progression and characteristics of aneuploidy, and differentiate among monosomy, trisomy 13, trisomy 18, and trisomy 21. HUHE.CUMM.16.6-7-1 – Summarize the characteristics of sex chromosome aneuploidies observed in humans, including Turner syndrome, Klinefelter syndrome, and XYY syndrome.

52. Define the term translocation and describe the two major types and their phenotypic consequences.

ANSWER:	Translocations move part of a chromosome to another, nonhomologous chromosome. There are two major types of translocations: reciprocal translocations and Robertsonian translocations. In a reciprocal translocation, two nonhomologous chromosomes exchange parts. No genetic information is gained or lost from the cell in the exchange, but genes are moved to new chromosomal locations. In some cases, there are no phenotypic effects, and the translocation is passed through a family for generations. Robertsonian translocations can produce genetically unbalanced gametes with duplicated or deleted chromosomal segments that can result in embryonic death or abnormal offspring.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-8 Structural Changes Within and Between Chromosomes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-8-3 – Describe the two major types of translocations and explain the relationship of Robertsonian translocations to Down syndrome.

53. Define the terms triploidy and autosomal trisomy and describe characteristics and consequences of each genetic disorder.

ANSWER:	The most common form of polyploidy in humans is triploidy. Triploidy occurs when the chromosomal number is three times the haploid number. Triploid newborns have multiple abnormalities, including an enlarged head fused fingers and toes, and malformations of the mouth, eyes, and genitals. The high rate of embryonic death and failure to survive after birth indicates that triploidy is a lethal condition. Most autosomal trisomies, a type of aneuploidy usually caused by nondisjunction, are lethal during prenatal development and account for up to 50% of the chromosomal abnormalities seen in miscarriages. Only a few autosomal trisomies result in live births. Down syndrome, trisomy 21, is the only autosomal trisomy that allows survival into adulthood.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-1 – Outline the common chromosomal abnormalities observed in humans. HUHE.CUMM.16.6-5-2 – Explain how the chromosomal abnormalities of triploidy and tetraploidy occur, and list the characteristics of each genetic condition.

54. There are no cases of -XX or Y individuals, but X individuals do exist. Propose an explanation for this statistic.

ANSWER:	Embryos without an X chromosome are not observed in miscarriages; these must be eliminated early in development—perhaps even before pregnancy is recognized. At least one copy of an X chromosome is essential for survival. The most likely explanation is that the X chromosome contains the majority of genes that encode for human development and that the Y chromosome is primarily the carrier of genes responsible for development into a male. Research has shown this to be the case.
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	6-7 Sex Chromosome Aneuploidy
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-7-2 – Discuss the conclusions that can be drawn from the study of sex chromosome disorders.

55. Explain how to determine if a nondisjunction occurred during meiosis I or meiosis II and what the genetic consequences are for the resulting fertilized gametes.

ANSWER:	If nondisjunction occurs in meiosis I, all gametes will be abnormal and carry either both members of a chromosomal pair or neither member of the pair. Nondisjunction in meiosis II produces 50% normal haploid cells and 50% abnormal cells, one with an extra copy of a chromosome and one missing a chromosome. Fertilization between gametes with an extra copy of a chromosome and a haploid gamete will result in trisomy; fusion of a haploid gamete and one missing a copy of a specific chromosome will result in monosomy. The phenotypic effects of aneuploidy range from minor physical symptoms to devastating and lethal conditions. Among survivors, phenotypic effects often include behavioral deficits and intellectual disability.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-3 – Describe the progression and characteristics of aneuploidy, and differentiate among monosomy, trisomy 13, trisomy 18, and trisomy 21.

56. Describe normal embryo formation and two mechanisms of nondisjunction represented in the figure and identify the consequences of these chromosomal anomalies.

ANSWER:	The figure represents uniparental disomy, which can be produced by several mechanisms involving nondisjunction. (a) Normal chromosomal configuration where gametes contain one copy of each chromosome and fertilization produces a zygote carrying two copies of a chromosome—one derived from each parent. (b) Nondisjunction in both parents, in which one gamete carries both copies of a chromosome and the other gamete is missing a copy of that chromosome. Fertilization produces a diploid zygote, but both copies of one chromosome are inherited from a single parent. (c) Nondisjunction in one parent, resulting in the loss of a chromosome. This gamete fuses with a normal gamete to produce a zygote monosomic for a chromosome. An error in the first mitotic division results in duplication of the monosomic chromosome, producing uniparental disomy.
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	6-10 Other Forms of Chromosome Changes
PREFACE NAME:	Embryo
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-10-2 – Describe the chromosomal changes that are not detectable by karyotype analysis, including uniparental disomy (UPD), copy number variants (CNVs), and fragile sites.

57. Explain how the terms diploid and haploid relate to human chromosome number in both autosomes and sex cells.

ANSWER:	Humans have 46 chromosomes that exist in pairs, with most cells having 23 homologous pairs, or 46 chromosomes. This is the diploid, or 2n, number of chromosomes. One member of each homologous pair is contributed by each parent. Certain cells, such as eggs and sperm (gametes), contain only one copy of each chromosome. These cells have 23 chromosomes, which is the haploid, or n, number of chromosomes.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-2 The Human Chromosome Set
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-2-1 – Identify the physical characteristics of a human chromosome and of a chromosome set.

58. Explain why geneticists believe that almost all chromosomally abnormal embryos and fetuses are eliminated as pregnancy progresses.

ANSWER:	Comparison of the number of chromosomal abnormalities detected by CVS (performed at 8 to 10 weeks of gestation) versus amniocentesis (at 16 weeks of gestation) shows that the abnormalities detected by CVS are two to five times more common than those detected by amniocentesis, which in turn are about two times more common than those found in newborns. This decrease in the frequency of chromosomal abnormalities during pregnancy provides evidence that almost all chromosomally abnormal embryos and fetuses are eliminated as pregnancy progresses.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-9 What Are Some Consequences of Aneuploidy?
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-9-2 – Outline three main consequences of aneuploidy in humans.

59. List at least three types of information provided by a karyotype and interpret the chromosomal structural abnormality written as 46,XX,t(18q).

ANSWER:	A karyotype provides several kinds of information: (1) the number of chromosomes present, (2) the number and type of sex chromosomes, (3) the presence or absence of individual chromosomes, and (4) the nature and extent of detectable structural abnormalities. The chromosome abnormality presented can be interpreted as a female who carries a translocation in the long arm of chromosome 18 but otherwise is chromosomally normal.
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	6-4 Analyzing Karyotypes
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-4-1 – List the cell types used to produce a karyotype, and describe the techniques used in karyotype analysis.

60. Describe two processes that would result in a triploid zygote.

ANSWER:	One process resulting in a triploid zygote is when homologous chromosomes fail to separate during meiosis I, the division in meiosis II will produce diploid gametes. The fertilized egg produced by fusion of this diploid gamete with a normal haploid gamete will be triploid. Another process is the simultaneous fusion of a haploid egg with two haploid sperm. This process is called dispermy.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	6-5 Variations in Chromosome Number
LEARNING OBJECTIVES:	HUHE.CUMM.16.6-5-1 – Outline the common chromosomal abnormalities observed in humans.

Chapter_07_Development_and_Sex_Determination

True / False

1. Bruce Reimer was born with ambiguous genitalia.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-1 Sex: Is It Nature or Nurture?
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-1-1 – Debate the psychological, social, and ethical consequences of the assumption that children are psychosexually neutral at birth.

2. Gonadal sex and sexual phenotype in males and females are produced by separate developmental pathways by the action of different gene sets.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-6 Defining Sex in Stages: Chromosomes, Gonads, and Hormones
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-6-1 – Identify the three levels that define the sex of an individual and demonstrate how genes and hormones interact to product male and female phenotypes.

3. Because females carry two X chromosomes and males carry only one, females have higher levels of all products encoded by genes on the X chromosome.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-1 – Define the term Barr body, and explain its role in dosage compensation in female mammals.

4. An embryo that is composed of a hollow ball of cells is called a blastocyst.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

5. The brain and nervous system of a developing embryo can only be damaged during the very early stages of development.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-1 – Define the term teratogen, describe some effects of teratogens on a fetus, and explain why first trimester embryos are especially sensitive to these agents.

6. The inheritance of sex-influenced traits can be dominant in one sex but recessive in the other.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-9 Sex-Related Phenotypic Effects
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-9-1 – Describe two situations in which males and females differ in the phenotypic expression of a trait, including sex-influenced traits and sex-limited traits

7. Sperm mature and are stored in the epididymis.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-2 – Define and label the terms scrotum, seminiferous tubule, spermatogenesis, spermatocyte, epididymis, vas deferens, ejaculatory duct, urethra, seminal vesicle, prostaglandin, prostate gland, bulbourethral gland, penis, (male) urinary bladder, and semen, identify the function of each in the male reproductive system.

8. Teratogenic effects of alcohol only occur during the first 12 weeks of pregnancy.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-2 – Describe the teratogenic effects of alcohol on a fetus.

9. Phenotypic sex is determined at the moment of fertilization.

	a.	True
	b.	False

ANSWER:	False
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-5 How Is Sex Determined?
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-5-1 – Identify the two factors involved in sex determination.

10. Complete androgen insensitivity causes XY males to become phenotypic females.

	a.	True
	b.	False

ANSWER:	True
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-7 Mutations Can Uncouple Chromosomal Sex from Phenotypic Sex
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-7-1 – Explain how genetic mutations can uncouple chromosomal sex from phenotypic sex and describe the phenotypes of two such genetic disorders.

Multiple Choice

11. The undifferentiated genitalia of an early human embryo develops into male genitalia under the influence of ____.

	a.	oxytocin
	b.	prostaglandin and DHT
	c.	prolactin
	d.	testosterone, AMH, and DHT
	e.	Wolfian duct inhibitors

ANSWER:	d
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-6 Defining Sex in Stages: Chromosomes, Gonads, and Hormones
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-6-1 – Identify the three levels that define the sex of an individual and demonstrate how genes and hormones interact to product male and female phenotypes.

12. The hormone oxytocin stimulates ____.

	a.	meiosis of oogonia
	b.	ovulation
	c.	implantation of the embryo
	d.	development of the fetal heart
	e.	contraction of uterine muscles during childbirth

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

13. Sex-influenced traits are expressed ____.

	a.	aftafter the formation of a Barr body
	b.	more in males than in females
	c.	as a result of hormone differences between males and females
	d.	only in males
	e.	only in females

ANSWER:	c
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-9 Sex-Related Phenotypic Effects
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-9-1 – Describe two situations in which males and females differ in the phenotypic expression of a trait, including sex-influenced traits and sex-limited traits

14. In addition to fertilizing the egg, sperm also ____.

	a.	assist the fertilizing sperm in penetrating the egg
	b.	trigger chemical changes in the egg
	c.	dissolve the outer barriers surrounding the oocyte
	d.	release chemicals to speed cell division in the zygote
	e.	trigger chemical changes in the egg that prevent the entry of more than one sperm

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

15. The part of the male reproductive system where sperm mature is known as the ____.

	a.	epididymis
	b.	bulbourethral gland
	c.	testis
	d.	seminal vesicle
	e.	ejaculatory duct

ANSWER:	a
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-2 – Define and label the terms scrotum, seminiferous tubule, spermatogenesis, spermatocyte, epididymis, vas deferens, ejaculatory duct, urethra, seminal vesicle, prostaglandin, prostate gland, bulbourethral gland, penis, (male) urinary bladder, and semen, identify the function of each in the male reproductive system.

16. A blastocyst ____.

	a.	releases hormones in the myometrium
	b.	releases the egg into the oviduct
	c.	implants in the endometrium
	d.	matures into a chorion
	e.	metabolically supports embryonic and fetal development

ANSWER:	c
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

17. Teratogens affect the ____ more than any other part of the fetal body.

	a.	central nervous system
	b.	upper limbs
	c.	heart
	d.	lower limbs
	e.	external genitalia

ANSWER:	a
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-1 – Define the term teratogen, describe some effects of teratogens on a fetus, and explain why first trimester embryos are especially sensitive to these agents.

18. A zygote is a(n) ____.

	a.	diploid cell
	b.	haploid cell
	c.	gamete
	d.	female gonad
	e.	male gonad

ANSWER:	a
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-1 – Define and label the terms zygote, sperm, oocyte, gamete, gonad, testis, and ovary, identify the function of each in the human reproductive system.

19. Seminal vesicles secrete fructose and ____ into the semen

	a.	DHT
	b.	oxytocin
	c.	testosterone
	d.	estrogen
	e.	prostaglandins

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-2 – Define and label the terms scrotum, seminiferous tubule, spermatogenesis, spermatocyte, epididymis, vas deferens, ejaculatory duct, urethra, seminal vesicle, prostaglandin, prostate gland, bulbourethral gland, penis, (male) urinary bladder, and semen, identify the function of each in the male reproductive system.

20. Any physical or chemical agent that brings about an increase in congenital malformations is called a(n) ____.

	a.	teratogen
	b.	hormone
	c.	ARX factor
	d.	cytocin
	e.	trophoblast

ANSWER:	a
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-1 – Define the term teratogen, describe some effects of teratogens on a fetus, and explain why first trimester embryos are especially sensitive to these agents.

21. The inner lining of the uterus that is shed at menstruation if fertilization has not occurred is called the ____.

	a.	cervix
	b.	endometrium
	c.	oogonium
	d.	chorion
	e.	epididymis

ANSWER:	b
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-3 – Define and label the terms follicle, ovulation, oviduct, uterus, endometrium, (female) urinary bladder, labia major, labia minor, clitoris, cervix, vagina, oogenesis, and oogonium, and identify the function of each in the female reproductive system.

22. In humans, body size, muscle mass, and patterns of fat distribution are types of ____ sex characteristics.

	a.	primary
	b.	secondary
	c.	tertiary
	d.	initial
	e.	mutable

ANSWER:	b
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-5 How Is Sex Determined?
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-5-1 – Identify the two factors involved in sex determination.

23. Pattern baldness is a(n) ____ trait.

	a.	X-linked
	b.	Y-linked
	c.	sex-linked
	d.	sex-limited
	e.	sex-influenced

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-9 Sex-Related Phenotypic Effects
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-9-1 – Describe two situations in which males and females differ in the phenotypic expression of a trait, including sex-influenced traits and sex-limited traits

24. In an XX embryo, ____ inactivation of one X chromosome usually occurs when the embryo has about 32 cells.

	a.	phenotypic
	b.	inhibited
	c.	cascading
	d.	selective
	e.	random

ANSWER:	e
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-3 – Explain how and when X inactivation occurs.

25. A Barr body is a(n) ____.

	a.	activated X chromosome
	b.	inactivated X chromosome
	c.	immature trophoblast
	d.	immature blastocyst
	e.	mature blastocyst

ANSWER:	b
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-1 – Define the term Barr body, and explain its role in dosage compensation in female mammals.

26. The pathway from ____ sex to ____ sex can be disrupted at several stages.

	a.	chromosomal; phenotypic
	b.	phenotypic; chromosomal
	c.	gonadal; chromosomal
	d.	gonadal; genotypic
	e.	phenotypic; gonadal

ANSWER:	a
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-7 Mutations Can Uncouple Chromosomal Sex from Phenotypic Sex
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-7-1 – Explain how genetic mutations can uncouple chromosomal sex from phenotypic sex and describe the phenotypes of two such genetic disorders.

27. During the 1968 Olympic Games, the International Olympic Committee performed an analysis of ____ on all female athletes in order to verify their sex.

	a.	Barr bodies
	b.	hormone levels
	c.	karyotypes
	d.	genitalia
	e.	phenotypes

ANSWER:	a
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-6 Defining Sex in Stages: Chromosomes, Gonads, and Hormones
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-6-1 – Identify the three levels that define the sex of an individual and demonstrate how genes and hormones interact to product male and female phenotypes.

28. The chorionic villi eventually form the placenta, a disc-shaped structure that ____.

	a.	releases sex hormones at appropriate times throughout pregnancy
	b.	initiates uterine contractions
	c.	binds to the zygote to accelerate organ development
	d.	nourishes the embryo throughout pregnancy
	e.	prevents infection by blocking the passage of microorganisms through the cervix during pregnancy

ANSWER:	d
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

29. The most important events in human development occur during the ____.

	a.	week before birth
	b.	month before birth
	c.	first trimester
	d.	second trimester
	e.	third trimester

ANSWER:	c
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

30. A fetus’s exposure to ____ is the leading preventable cause of birth defects.

	a.	alcohol
	b.	X-rays
	c.	viruses
	d.	thalidomide
	e.	Toxoplasma gondii

ANSWER:	a
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-2 – Describe the teratogenic effects of alcohol on a fetus.

Completion

31. X inactivation can lead to ____________________ in females who are heterozygous for X-linked genes.

ANSWER:	mosaicism mosaics mosaic
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-3 – Explain how and when X inactivation occurs.

32. The process of ____________________ equalizes the dosage of functional genes carried on the X chromosome in males and females.

ANSWER:	X inactivation
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-3 – Explain how and when X inactivation occurs.

33. The duct between a testis and a seminal vesicle used for the transport of sperm is the ____________________.

ANSWER:	vas deferens
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-2 – Define and label the terms scrotum, seminiferous tubule, spermatogenesis, spermatocyte, epididymis, vas deferens, ejaculatory duct, urethra, seminal vesicle, prostaglandin, prostate gland, bulbourethral gland, penis, (male) urinary bladder, and semen, identify the function of each in the male reproductive system.

34. The process of ____________________ equalizes the amount of X chromosome gene products in both sexes.

ANSWER:	dosage compensation
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-2 – Summarize the Lyon hypothesis and the process of dosage compensation in mammalian females, and discuss the concept of mosaicism.

35. Most of the protein eaten by the mother during the third trimester of pregnancy is used for fetal brain and ____________________ system growth and development.

ANSWER:	nervous
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

36. In the male reproductive system, the ____________________ secretes a milky, alkaline fluid that neutralizes acidic vaginal secretions and enhances sperm viability.

ANSWER:	prostate gland prostate
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-2 – Define and label the terms scrotum, seminiferous tubule, spermatogenesis, spermatocyte, epididymis, vas deferens, ejaculatory duct, urethra, seminal vesicle, prostaglandin, prostate gland, bulbourethral gland, penis, (male) urinary bladder, and semen, identify the function of each in the male reproductive system.

37. The lower neck of the uterus opening into the vagina is the ____________________.

ANSWER:	cervix
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-3 – Define and label the terms follicle, ovulation, oviduct, uterus, endometrium, (female) urinary bladder, labia major, labia minor, clitoris, cervix, vagina, oogenesis, and oogonium, and identify the function of each in the female reproductive system.

38. Children born with ____________________ have genital structures that are neither fully male nor fully female.

ANSWER:	ambiguous genitalia
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-1 Sex: Is It Nature or Nurture?
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-1-1 – Debate the psychological, social, and ethical consequences of the assumption that children are psychosexually neutral at birth.

39. Females outnumber males in the tertiary sex ratio because genetic and ____________________ factors cause higher death rates among males.

ANSWER:	environmental
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-5 How Is Sex Determined?
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-5-2 – Describe how the sex ratio in humans changes with stages of life.

40. At term, ____________________ changes initiate and drive the events surrounding birth.

ANSWER:	hormonal
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

41. Female gametes complete meiosis II at ____________________.

ANSWER:	fertilization
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-4 – Describe the differences in the timing of meiosis and gamete formation in males and females.

42. The formation of _____ depends on gene action, interactions within the embryo, interaction with other embryos that may be in the uterus, and interactions with the maternal environment.

ANSWER:	male and female reproductive structures
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-6 Defining Sex in Stages: Chromosomes, Gonads, and Hormones.
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-6-1 – Identify the three levels that define the sex of an individual and demonstrate how genes and hormones interact to product male and female phenotypes.

43. A condition called ____________________ results in individuals having both male and female sexual structures at different times in their lives.

ANSWER:	gonadal intersexuality
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-7 Mutations Can Uncouple Chromosomal Sex from Phenotypic Sex
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-7-1 – Explain how genetic mutations can uncouple chromosomal sex from phenotypic sex and describe the phenotypes of two such genetic disorders.

44. Duchenne muscular dystrophy is, for all practical purposes, a(n) ____________________ trait.

ANSWER:	sex-limited
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-9 Sex-Related Phenotypic Effects
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-9-1 – Describe two situations in which males and females differ in the phenotypic expression of a trait, including sex-influenced traits and sex-limited traits

45. The health effects of X-rays on a fetus depend on the amount of ____________________ and the ____________________ of the fetus.

ANSWER:	radiation; age
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-1 – Define the term teratogen, describe some effects of teratogens on a fetus, and explain why first trimester embryos are especially sensitive to these agents.

46. By the end of the first trimester of pregnancy, all of the major ____________________ have formed and are functional.

ANSWER:	organ systems organs
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1 – Describe the events of fertilization and early embryonic cell division in humans.

47. Chromosomal sex of a fetus with the sex chromosomes XXY is almost always ____________________.

ANSWER:	male
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-5 How Is Sex Determined?
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-5-1 – Identify the two factors involved in sex determination.

48. A collection of birth defects caused by alcohol consumption during pregnancy is known as ____________________.

ANSWER:	fetal alcohol syndrome FAS
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-2 – Describe the teratogenic effects of alcohol on a fetus.

49. In 2012, the International Olympic Committee began using tests that measure the levels and the body’s response to the male hormone ____________________ as a means of distinguishing females from males when sex was questionable.

ANSWER:	testosterone
DIFFICULTY:	Bloom’s: Remember
REFERENCES:	7-6 Defining Sex in Stages; Chromosomes, Gonads, and Hormones
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-6-1 – Identify the three levels that define the sex of an individual and demonstrate how genes and hormones interact to product male and female phenotypes.

50. The small region of an inactivated X chromosome that is not inactivated contains ____________________ homologous to those on the Y chromosome.

ANSWER:	genes
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-3 – Explain how and when X inactivation occurs.

Essay

51. Describe the stages at which genetic sex, gonadal sex, and phenotypic sex are established.

ANSWER:	The sex of an individual is formed in three stages. The first stage—chromosomal sex—occurs at fertilization with the formation of a zygote with either an XX or XY chromosome pair. During the second stage, in males, the undifferentiated gonads develop into testes and, in females, they develop into ovaries. During the third stage in males, testosterone (converted into DHT) directs the formation of the penis and scrotum. In females, no DHT is present, and the genital tubercle develops into the clitoris, the genital folds form the labia minora, and the labioscrotal swellings form the labia majora.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-6 Defining Sex in Stages: Chromosomes, Gonads, and Hormones
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-6-1 – Identify the three levels that define the sex of an individual and demonstrate how genes and hormones interact to product male and female phenotypes.

52. Explain how X inactivation can result in female mosaicism and give examples.

ANSWER:	Female mammals are constructed of two different cell types. Some cells express alleles from the father’s X chromosome and some cells express alleles from the mother’s X chromosome. Early in embryonic development, one X chromosome in each cell will be inactivated. The inactivation will occur randomly. If a visible trait is linked to an inactivated X chromosome, any cells derived from the original inactivated cell will not display the trait. The pattern of coat color in some mice and in some cats, and the patches of affected and unaffected skin on a woman with anhidrotic ectodermal dysplasia represent groups of cells descended from a single cell in which the inactivation event occurred.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-1 – Define the term Barr body, and explain its role in dosage compensation in female mammals.

53. Describe how the previous assumption regarding the development of sexual identity and the treatment for ambiguous genitalia has changed in recent years.

ANSWER:	Most scientists believed that children are psychosexually neutral at birth and that nurture had more to do with sexual roles than nature. Males with a small or malformed penis were surgically altered into females because in reconstructive genital surgery it is easier to make a vagina than a penis. However, investigators have concluded that it is wrong to assume that sexual identity is neutral at birth and that it can be shaped by the environment. This conclusion was confirmed by studies of children born as males with ambiguous genitals and surgically reassigned as females. Currently, guidelines for surgical sex reassignment use karyotypes to establish chromosomal sex and the presence of ovaries or testes as major considerations. Surgical reassignment of infants is now rarely done.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-1 Sex: Is It Nature or Nurture?
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-1-1 – Debate the psychological, social, and ethical consequences of the assumption that children are psychosexually neutral at birth.

Figure 7.6

54. The accompanying figure illustrates the process of human development from fertilization to implantation. Describe what happens from day 1 through days 6-7 of this process.

ANSWER:	Students should outline how a blastocyst forms into an early embryo, and implants itself in the endometrium. They may include some of the following steps. DAYS 1–2. The first cleavage furrow extends between the two polar bodies. Later cleavage so cells become asymmetrically arranged. They are loosely organized with space between them. DAY 3. After the third cleavage, cells abruptly huddle into a compacted ball, and tight junctions among the outer cells stabilize. Gap junctions formed along the interior cells enhance intercellular communication. DAY 4. By 96 hours, the embryo is a solid ball of cells called a morula. Cells of the surface layer will function in implantation and give rise to a membrane, the chorion. DAY 5. A fluid-filled cavity called the blastocoel forms in the morula and the inner cell mass forms. Differentiation occurs in the inner cell mass and gives rise to the embryo proper. This embryonic stage is the blastocyst. DAYS 6–7 . Some of the blastocyst’s surface cells attach themselves to the endometrium and start to burrow into it. Implantation has started.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
PREFACE NAME:	Figure 7.6
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-3-1: – Describe the events of fertilization and early embryonic cell division in humans.

55. How is the timing of gamete formation in females different than that in males?

ANSWER:	In males, spermatogenesis begins at puberty and takes about 48 days: 16 for meiosis I, 16 for meiosis II, and 16 to convert the spermatid into the mature sperm. Each of the four products of meiosis forms sperm. The timing of gamete formation in females is much different than in males. In oogenesis, cells in the ovaries (called oogonia) begin meiosis I during embryonic development and then stop. After puberty, usually one oocyte per menstrual cycle completes the first meiotic division, is released from the ovary, and moves into the oviduct. Fertilization takes place in the oviduct. Fertilized eggs quickly complete meiosis II, producing a diploid zygote. Unfertilized eggs disintegrate within 24 hours after ovulation. Each month until menopause, another oocyte completes meiosis I and is released from the ovary. Altogether, a woman produces and releases about 450 oocytes during the reproductive phase of her life.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-2 The Human Reproductive System
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-4 – Describe the differences in the timing of meiosis and gamete formation in males and females.

56. As sperm are transported through the ducts system, what secretions are added from which three sets of glands to make up semen?

ANSWER:	The seminal vesicles secrete fructose, a sugar that serves as an energy source for the sperm, and prostaglandins, locally acting chemical messengers that stimulate contraction of the female reproductive system to assist in sperm movement. The prostate gland secretes a milky, alkaline fluid that neutralizes acidic vaginal secretions and enhances sperm viability. The bulbourethral glands secrete a mucuslike substance that provides lubrication for intercourse. Together, the sperm and these various glandular secretions make up semen, a mixture that is about 95% secretions and about 5% spermatozoa.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-3 A Survey of Human Development from Fertilization to Birth
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-2-2 – Define and label the terms scrotum, seminiferous tubule, spermatogenesis, spermatocyte, epididymis, vas deferens, ejaculatory duct, urethra, seminal vesicle, prostaglandin, prostate gland, bulbourethral gland, penis, (male) urinary bladder, and semen, identify the function of each in the male reproductive system.

57. Explain why a pregnant woman should not have an abdominal X-ray and identify the possible consequences to the fetus if she does.

ANSWER:	Pregnant women should avoid all unnecessary X-rays. Radiation, especially medical X-rays, can be a teratogen. The human embryo is most sensitive to teratogens during the early stages of pregnancy. Large doses of radiation during weeks 2 –18 can affect the brain and central nervous system and significant radiation exposure before birth can increase the risk of cancer later in life. Pregnant women should avoid all unnecessary X-rays.
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	7-4 Teratogens Are a Risk to the Developing Fetus
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-4-1 – Define the term teratogen, describe some effects of teratogens on a fetus, and explain why first trimester embryos are especially sensitive to these agents.

58. Describe the interactions between genes and the environment in the sex determination of some reptiles; explain their relevance to human sex determination.

ANSWER:	Maleness and femaleness are determined by complex interactions between genes and the environment. Sex determination in some reptiles illustrates the role of environmental factors in determining sex. The internal temperature of the nest in which the eggs develop determines the sex of the offspring. In some species, higher temperatures produce females and lower temperatures produce males. In other species, the opposite is true. From the study of humans, it is clear that someone having an XX or XY chromosome set does not always mean someone develops as a female or male. The outcome depends on the distribution and expression of genes on the X and Y chromosomes and interactions between genes on these chromosomes with many different environmental factors.
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	7-5 How Is Sex Determined? \| 7-6 Defining Sex in Stages: Chromosomes, Gonads, and Hormones.
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-5-1 – Identify the two factors involved in sex determination.

59. Explain how sex-limited genes are inherited and give an example of this type of inheritance.

ANSWER:	Sex-limited genes are inherited by both males and females but are normally expressed only in one sex. An example is an autosomal dominant trait that controls precocious puberty. This gene is expressed in heterozygous males but not in heterozygous females. Heterozygous females are unaffected but pass this trait on to half of their sons, making it hard to distinguish this trait from a sex-linked gene. Genes that deal with traits such as breast development in females and facial hair in males are other examples of sex-limited genes, as are virtually all other genes that deal with secondary sexual characteristics.
DIFFICULTY:	Bloom’s: Understand
REFERENCES:	7-9 Sex-Related Phenotypic Effects
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-9-1 – Describe two situations in which males and females differ in the phenotypic expression of a trait, including sex-influenced traits and sex-limited traits

60. Describe the Lyon hypothesis.

ANSWER:	Mary Lyon studied the inheritance of coat color in mice. Her discoveries, along with those of other scientists, led her to propose her hypothesis about how dosage compensation works. She concluded the following: Only one X chromosome is genetically active in the body cells of female mammals. The second X chromosome is inactivated and tightly coiled to form the Barr body. The inactivated chromosome can come from either parent. Inactivation takes place early in development. After four to five rounds of mitosis following fertilization, each cell of the embryo randomly inactivates one X chromosome. This inactivation is permanent (except in germ cells), and all descendants of a particular cell will have the same X chromosome inactivated. Because genes on only one X chromosome are expressed in females, this equalizes the amounts of products from X-linked genes in males and females. The Lyon hypothesis means that female mammals are actually mosaics, constructed of two different cell types.
DIFFICULTY:	Bloom’s: Analyze
REFERENCES:	7-8 Equalizing the Expression of X Chromosome Genes in Males and Females
LEARNING OBJECTIVES:	HUHE.CUMM.16.7-8-1 – Define the term Barr body, and explain its role in dosage compensation in female mammals.