Deck 7: Development and Sex Determination

Question 1

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

Answer 1

True

Question 2

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

Answer 2

True

Question 3

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 3

A

Question 4

Complete androgen insensitivity causes XY males to become phenotypic females.

Question 5

Seminal vesicles secrete fructose and ____ into the semen

A) DHT
B) oxytocin
C) testosterone
D) estrogen
E) prostaglandins

Question 6

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

Question 7

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

Question 8

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

Question 9

Phenotypic sex is determined at the moment of fertilization.

Question 10

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

Question 11

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

Question 12

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

Question 13

Sperm mature and are stored in the epididymis.

Question 14

A zygote is a(n)____.

A) diploid cell
B) haploid cell
C) gamete
D) female gonad
E) male gonad

Question 15

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

Question 16

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

Question 17

Bruce Reimer was born with ambiguous genitalia.

Question 18

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.

Question 19

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

Question 20

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

Question 21

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

Question 22

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

Question 23

Pattern baldness is a(n)____ trait.

A) X-linked
B) Y-linked
C) sex-linked
D) sex-limited
E) sex-influenced

Question 24

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

Question 25

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

Question 26

A Barr body is a(n)____.

A) activated X chromosome
B) inactivated X chromosome
C) immature trophoblast
D) immature blastocyst
E) mature blastocyst

Question 27

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

Question 28

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

Question 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

Question 30

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

Question 31

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

Question 32

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

Question 33

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

Question 34

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

Question 35

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

Question 36

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

Question 37

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

Question 38

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

Question 39

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

Question 40

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

Question 41

Describe the Lyon hypothesis.

Question 42

Female gametes complete meiosis II at ____________________.

Question 43

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

Question 44

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

Question 45

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

Question 46

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.

Question 47

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

Question 48

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

Question 49

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

Question 50

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

Question 51

Figure 7.6

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.

Question 52

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

Question 53

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

Question 54

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

Question 55

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

Question 56

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

Question 57

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.

Question 58

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

Question 59

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

Question 60

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