Deck 21: Human Development and Genetics

Question 1

Which of the following statements are true of fertilization and embryonic development? (Read carefully and select all of the correct statements.)

A)Fertilization usually takes place within the body of the uterus.
B)Implantation usually occurs 5 to 8 hours after fertilization.
C)The zygote has the diploid number of chromosomes and begins to divide by mitosis.
D)The first 18 weeks of human development are the embryonic phase.
E)In fertilization,the tail of the sperm cell creates an opening in the egg cell membranE.
F)The cells of an 8-cell embryo are still very similar to one another.
G)The outer layer of the blastocyst will become the embryo.
H)Cell divisions of the zygote are collectively called cleavage.

Answer 1

C,F,H

Question 2

The early embryonic stage that consists of a hollow sphere of cells with an inner cell mass is the:

A)morula
B)blastocyst
C)16-cell stage
D)chorion

Answer 2

B

Question 3

Which of the following statements are true of labor and delivery? (Read carefully and select all of the correct statements.)

A)The hormone oxytocin from the anterior pituitary promotes strong contractions of the myometrium.
B)The uterine cervix dilates during the first stage of labor.
C)The amniotic sac ruptures during the second stage of labor.
D)If the fetus is positioned sideways,the third stage of labor will be prolonged.
E)The placenta is delivered soon after the delivery of the infant.
F)Decreasing progesterone at the end of gestation increases the contractility of the myometrium.

Answer 3

B,E,F

Question 4

Which of the following statements are true of the embryonic membranes? (Read carefully and select all of the correct statements.)

A)The amniotic sac surrounds the fetus and contains fluid.
B)The yolk sac provides the first nutrients for the embryo.
C)The chorion will form the maternal part of the placenta.
D)The first fetal blood cells are made by the amnion.
E)The embryonic membranes are not part of the fetus,but are made of fetal tissuE.
F)The yolk sac becomes a cushion for the embryo.

Question 5

Which of the following statements are true of the placenta and fetal circulation? (Read carefully and select all of the correct statements.)

A)The umbilical arteries carry oxygen and nutrients to the fetus.
B)The foramen ovale permits blood to flow from the left atrium to the right atrium.
C)The ductus venosus takes blood to the superior vena cava after bypassing the lungs.
D)The ductus arteriosus takes blood from the aorta to the pulmonary artery.
E)The placenta is made of both fetal and maternal tissuE.
F)Fetal carbon dioxide is brought to the placenta by the umbilical vein.

Question 6

A human zygote contains how many chromosomes?

A)23
B)46
C)46 pairs
D)23 pairs plus two sex chromosomes

Question 7

The early embryonic stage that is a solid sphere of cells is the:

A)morula,and the cells are all very similar
B)dermoblast,and the cells are all very similar
C)morula,and the cells are in three germ layers
D)dermoblast,and the cells are in three germ layers

Question 8

Which of the following statements are true of dominant-recessive inheritance? (Read carefully and select all of the correct statements.)

A)A heterozygous offspring will have the dominant characteristic in the phenotype.
B)A homozygous offspring will have the recessive characteristic in the phenotype.
C)If a recessive trait does not appear in a family for two generations,the gene for it is no longer present.
D)If Mom and Dad both have blue eyes,the chance for a child of theirs to have brown eyes is only 50%.
E)If Mom and Dad both have brown eyes,the chance for a child of theirs to have blue eyes is 50%.
F)A trait is considered dominant when it is more common (frequent)in a population than its recessive counterpart.

Question 9

Which of the following statements are true of sex-linked inheritance? (Read carefully and select all of the correct statements.)

A)The Y chromosome has more genes than does the X chromosome,and they are all dominant.
B)A woman with one gene for a sex-linked trait is a carrier of the trait.
C)The dominant gene on the Y chromosome is expressed when the corresponding gene on the X chromosome is missing.
D)The dominant gene on the Y chromosome is expressed when the corresponding gene on the X chromosome is recessive.
E)Men can be carriers only if the gene for the trait on the Y chromosome is recessivE.
F)A daughter acquires a sex-linked trait from both parents,but a son acquires such a trait only from his mother.

Question 10

Fertilization usually takes place in the:

A)vagina
B)uterus
C)fallopian tube
D)ovary

Question 11

The portion of the blastocyst that contains the potential embryo is the:

A)ectoderm
B)trophoblast
C)inner cell mass
D)endoderm

Question 12

Which of the following statements are true of the infant at birth? (Read carefully and select all of the correct statements.)

A)The lungs are expanded by the first breaths and pulmonary circulation increases.
B)The foramen ovale between the ventricles is closed.
C)The ductus arteriosus dilates to help establish pulmonary circulation.
D)After the umbilical cord is cut,the ductus venosus constricts.
E)An Apgar score is an assessment only of the newborn's breathin
G)
F)A newborn may have slight jaundice,because the liver is not fully mature.

Question 13

Which of the following statements are true of genes and chromosomes? (Read carefully and select all of the correct statements.)

A)Chromosomes are made of DNA and protein; genes are made of DNA.
B)A homologous pair of chromosomes consists of maternal and paternal chromosomes with genes for the same traits.
C)A human diploid body cell has 23 pairs of autosomes.
D)The sex chromosomes are XX for women and YY for men.
E)The DNA for a gene is the sequence of bases in the triplets for the amino acids that make up the protein that the gene is the code for.
F)The genome of a species is the number of chromosomes in one cell.

Question 14

A zygote begins a series of cell divisions called:

A)differentiation,and the process is mitosis
B)cleavage,and the process is meiosis
C)differentiation,and the process is meiosis
D)cleavage,and the process is mitosis

Question 15

Which of the following statements are true of genetics? (Read carefully and select all of the correct statements.)

A)Genotype is the assortment of alleles (genes)that are actually present in a person.
B)The same phenotype may be possible with two different genotypes.
C)The same genotype may be possible with two different phenotypes.
D)In a homozygous pair of alleles,both are the same.
E)In a heterozygous pair of alleles,both are either maternal or paternal.
F)The homozygous phenotype for a trait is always different from the heterozygous phenotype.

Question 16

When a zygote undergoes cleavage,the process involved is:

A)mitosis
B)meiosis
C)implantation
D)fertilization

Question 17

The stem cells of a blastocyst are found in:

A)the inner cell mass
B)the outer cell mass
C)the trophoblast
D)all of these

Question 18

Which of the following statements are true of the primary germ layers of the embryo? (Read carefully and select all of the correct statements.)

A)The ectoderm gives rise to the nervous system.
B)Mesoderm forms most of the liver and pancreas.
C)Bones come primarily from endoderm.
D)The lungs are epithelial tissue from the ectoderm.
E)The stomach lining is an inside surface and is of endodermal origin.
F)Most organs have tissues from all three germ layers.

Question 19

Which of the following statements are true of multiple allele inheritance? (Read carefully and select all of the correct statements.)

A)More than two alleles for the trait exist,but an individual will have only two of them.
B)At least one of the alleles will be dominant over another.
C)A child may have a phenotype that is different from that of both parents.
D)A child may have a genotype that is different from that of both parents.
E)The human ABO blood group has three alleles and four possible blood types.
F)In the ABO group,the recessive phenotype is the most frequent in the human population.

Question 20

Which of the following statements are true of the placental hormones? (Read carefully and select all of the correct statements.)

A)The chorion of the embryo produces hCG to maintain the corpus luteum during early pregnancy.
B)Contractions of the myometrium are inhibited by the estrogen produced by the placenta.
C)Estrogen and progesterone begin to stimulate milk production toward the end of pregnancy.
D)Progesterone is first produced by the corpus luteum,then by the placenta.
E)The secretion of FSH and LH by the anterior pituitary is inhibited by estrogen and progesteronE.
F)Relaxin increases the stretchiness of the ligaments of the pubic symphysis.

Question 21

The embryonic membrane that contains fluid to cushion the embryo is the:

A)chorion
B)amnion
C)yolk sac
D)umbilical cord

Question 22

Which statement is NOT true of the events surrounding fertilization?

A)The sperm and egg each contribute 23 chromosomes.
B)Fertilization usually takes place in the fallopian tube.
C)The zygote begins to divide by meiosis to produce two cells,then four cells,and so on.
D)The hollow sphere of cells that is formed is called a blastocyst.

Question 23

The portion of the blastocyst that secretes enzymes to permit implantation is the:

A)ectoderm
B)trophoblast
C)inner cell mass
D)endoderm

Question 24

During gestation,at the end of the period of embryonic growth:

A)the cells have specialized into three germ layers
B)the first tissue has formed
C)many tissues have formed,but are not yet organized
D)all of the organ systems have been formed

Question 25

In the gestation period,the period of fetal growth lasts:

A)the first 32 weeks of gestation
B)the first 20 weeks of gestation
C)the last 20 weeks of gestation
D)the last 32 weeks of gestation

Question 26

In the gestation period,the period of embryonic growth lasts:

A)the first 8 weeks of gestation
B)the first 16 weeks of gestation
C)the last 8 weeks of gestation
D)the last 32 weeks of gestation

Question 27

In the early embryo,the mesoderm gives rise to the:

A)lens and cornea of the eye
B)skeletal muscles
C)lungs
D)liver

Question 28

In the early embryo,the nervous system and epidermis are derived from the:

A)ectoderm
B)mesoderm
C)endoderm
D)intraderm

Question 29

Which of these embryonic structures is NOT paired with the correct primary germ layer from which it develops?

A)brain - ectoderm
B)kidneys - mesoderm
C)lungs - ectoderm
D)dermis - mesoderm

Question 30

Normal implantation of the blastocyst takes place in the:

A)endometrium
B)myometrium
C)serosa
D)fallopian tube

Question 31

The average gestation period lasts:

A)36 weeks
B)40 weeks
C)46 weeks
D)50 weeks

Question 32

The embryonic membrane that forms the first blood cells is the:

A)chorion
B)amnion
C)yolk sac
D)umbilical cord

Question 33

The embryonic membrane that forms the fetal portion of the placenta is the:

A)chorion
B)amnion
C)yolk sac
D)umbilical cord

Question 34

An ectopic pregnancy is one in which:

A)fertilization is delayed
B)cleavage is very slow
C)the stem cells do not specialize as they should
D)the blastocyst becomes implanted outside the uterus

Question 35

In the early embryo,the ectoderm gives rise to the:

A)nerves
B)dermis and fat
C)lungs
D)bones

Question 36

In the early embryo,the liver and pancreas are derived from the:

A)ectoderm
B)mesoderm
C)endoderm
D)intraderm

Question 37

The embryonic membrane that has villi to provide nourishment for the early embryo is the:

A)chorion
B)amnion
C)yolk sac
D)umbilical cord

Question 38

Which of these embryonic structures is NOT paired with the correct primary germ layer from which it develops?

A)epidermis - ectoderm
B)liver - endoderm
C)heart - mesoderm
D)skeletal muscles - ectoderm

Question 39

In the early embryo,the endoderm gives rise to the:

A)nasal mucosa
B)bones
C)dermis
D)pancreas

Question 40

In the early embryo,the heart and skeletal muscles are derived from the:

A)ectoderm
B)mesoderm
C)endoderm
D)intraderm

Question 41

The stage of labor during which the cervix begins to dilate is the:

A)first stage
B)second stage
C)third stage
D)fourth stage

Question 42

For the embryo,the chorion:

A)contains fluid and absorbs shock
B)forms the first cells of the immune system
C)forms the fetal portion of the placenta
D)all of these

Question 43

Blood is carried from the placenta to the fetus by the:

A)ductus venosus
B)umbilical vein
C)blood sinuses
D)umbilical arteries

Question 44

The stage of labor during which the placenta is delivered is the:

A)first stage
B)second stage
C)third stage
D)fourth stage

Question 45

For the embryo,the amnion:

A)contains fluid and is a cushion
B)provides oxygen and nutrients
C)forms the first blood cells
D)forms part of the placenta

Question 46

The placental hormone that inhibits contractions of the myometrium during pregnancy is:

A)FSH
B)hCG
C)estrogen
D)progesterone

Question 47

In the placenta:

A)fetal blood moves into maternal circulation to pick up oxygen and nutrients
B)maternal blood moves into fetal circulation to deliver oxygen and nutrients
C)maternal red blood cells move into fetal circulation to deliver oxygen
D)oxygen is exchanged by diffusion from maternal blood vessels to fetal blood vessels

Question 48

The site of exchanges between maternal blood and fetal blood is the:

A)umbilical arteries
B)umbilical vein
C)placenta
D)myometrium

Question 49

The placenta is formed by:

A)the maternal endometrium and fetal chorion
B)the maternal myometrium and fetal amnion
C)the maternal endometrium and fetal amnion
D)the maternal myometrium and fetal chorion

Question 50

The placental hormones that prepare the mammary glands for lactation are:

A)progesterone and hCG
B)hCG and estrogen
C)estrogen and progesterone
D)progesterone and relaxin

Question 51

For the embryo,the yolk sac:

A)provides a cushion
B)forms the first blood cells
C)provides nourishment
D)forms the fetal portion of the placenta

Question 52

Blood is carried from the fetus to the placenta by the:

A)ductus arteriosus
B)umbilical vein
C)blood sinuses
D)umbilical arteries

Question 53

Which statement is NOT true of the embryonic membranes?

A)The amnion contains fluid to cushion the embryo.
B)The chorion is the outermost area of the membranes.
C)The yolk sac will provide nourishment for the early embryo.
D)The yolk sac forms the first blood cells.

Question 54

The function of the hormone hCG is to:

A)inhibit the anterior pituitary gland
B)promote rapid growth of the embryo
C)stop the secretion of FSH and LH during pregnancy
D)stimulate the corpus luteum to secrete estrogen and progesterone

Question 55

The umbilical arteries contain blood that has a high level of:

A)carbon dioxide and nutrients
B)oxygen and nutrients
C)oxygen and waste products
D)carbon dioxide and waste products

Question 56

The stage of labor during which the infant is delivered is the:

A)first stage
B)second stage
C)third stage
D)fourth stage

Question 57

Which statement is NOT true of the placenta and umbilical blood vessels?

A)Two umbilical arteries take blood to the fetus.
B)Maternal blood does not mix with fetal blood in the placenta.
C)The umbilical vein contains blood with a high level of oxygen.
D)In the placenta,exchanges take place by diffusion and active transport.

Question 58

The umbilical vein contains blood that has a high level of:

A)carbon dioxide and nutrients
B)oxygen and nutrients
C)oxygen and waste products
D)carbon dioxide and waste products

Question 59

The placental hormone that maintains the corpus luteum during early pregnancy is:

A)hCG
B)estrogen
C)FSH
D)progesterone

Question 60

The placental hormones that inhibit ovulation during pregnancy are:

A)FSH and hCG
B)LH and progesterone
C)estrogen and hCG
D)estrogen and progesterone

Question 61

A human cell contains how many pairs of autosomes?

A)22 pairs
B)23 pairs
C)44 pairs
D)46 pairs

Question 62

A person has two genes for each genetic trait; these genes are called:

A)positive and negative
B)maternal and paternal
C)present and absent
D)dominant and recessive

Question 63

After birth,the infant's pulmonary circulation is increased because the foramen ovale ____ and the ductus arteriosus ____.

A)is closed/constricts
B)is opened/constricts
C)is closed/dilates
D)is opened/dilates

Question 64

The autosomes a person has are:

A)all the chromosomes
B)the maternal or paternal set of chromosomes
C)the chromosomes other than the sex chromosomes
D)the dominant chromosomes

Question 65

A homologous pair of chromosomes contains genes for:

A)the same traits
B)different traits
C)related traits
D)recessive traits

Question 66

Homologous chromosomes are a pair of chromosomes that may also be called:

A)dominant and recessive
B)active and inactive
C)paired and unpaired
D)maternal and paternal

Question 67

After birth,the fetal ductus arteriosus ____ so that ____ blood will flow to the fetal lungs.

A)constricts/less
B)dilates/more
C)constricts/more
D)dilates/less

Question 68

The sex chromosomes in men are called:

A)XX
B)YY
C)XY
D)XZ

Question 69

A person who is heterozygous for a particular trait has:

A)an extra gene (allele)
B)two similar genes (alleles)
C)only one gene (allele)
D)two different genes (alleles)

Question 70

A pair of chromosomes that has maternal and paternal genes for the same traits is said to be a ____ pair.

A)heterozygous
B)homologous
C)homogeneous
D)heterogeneous

Question 71

The stage of labor during which the amniotic sac ruptures is the:

A)first stage
B)second stage
C)third stage
D)fourth stage

Question 72

Which statement is NOT true of human chromosomes?

A)The diploid number is 46.
B)Chromosome pairs number 2 and 13 are autosomes.
C)The sex chromosomes for women are XX.
D)A homologous pair is either maternal or paternal.

Question 73

The sex chromosomes in women are called:

A)XX
B)YY
C)XY
D)XZ

Question 74

After birth,the fetal foramen ovale is ____ in order to ____ pulmonary circulation.

A)closed/decrease
B)opened/increase
C)opened/decrease
D)closed/increase

Question 75

The genetic code in cells is the ____ of the ____.

A)DNA/ribosomes
B)RNA/chromosomes
C)RNA/nucleus
D)DNA/chromosomes

Question 76

A gene is a specific part of ____ and is the genetic code for one ____.

A)DNA/ chromosome
B)RNA/ protein
C)DNA/ protein
D)RNA/ chromosome

Question 77

A gene is the genetic code for one:

A)protein
B)cell
C)chromosome
D)organ

Question 78

After birth,the infant's ductus venosus constricts because:

A)more blood is returning from the lungs
B)the umbilical arteries have been cut
C)more blood is flowing to the lungs
D)the umbilical vein has been cut

Question 79

The hormone that causes strong contractions of the uterus during labor is:

A)oxytocin
B)estrogen
C)hCG
D)progesterone

Question 80

A person who is homozygous for a particular trait has:

A)only one gene (allele)
B)two similar genes (alleles)
C)an extra gene (allele)
D)two different genes (alleles)