5) Which of the following is not part of oocyte activation?
A) softening of the zona pellucida
B) influx of sodium ion
C) membrane depolarization
D) release of calcium ion from smooth ER
E) discharge of exocytotic vesicles adjacent to the oocyte membrane

A) softening of the zona pellucida

6) Polyspermy results in
A) twins.
B) fetuses with different fathers.
C) haploid individuals.
D) chimeric adults.
E) a nonfunctional zygote.

E) a nonfunctional zygote.

7) During amphimixis,
A) sperm become haploid.
B) the ovum finishes meiosis II.
C) the male and female pronuclei fuse.
D) meiosis occurs.
E) gametes are formed.

C) the male and female pronuclei fuse.

8) The site where fertilization normally occurs is in the
A) cervix.
B) fimbrae.
C) uterine wall near the fundus.
D) outer one-third of the uterine tube.
E) union of the vagina and uterus.

D) outer one-third of the uterine tube.

9) The layer of follicle cells that surround the unfertilized egg is called the
A) zona pellucida.
B) corona radiata.
C) Graafian follicle.
D) functional zone.
E) tunica follicularis.

B) corona radiata.

10) Block to polyspermy is prevented by the ________ reaction.
A) metabolic
B) gamete
C) gollumina
D) cortical
E) polarity

D) cortical

11) The cell that directly results from the fusion of a secondary oocyte and a single sperm is called a(n)
A) ootid.
B) gastrula.
C) blastula.
D) morula.
E) zygote.

E) zygote.

12) Sperm release ________ to break down the bonds between adjacent follicle cells surrounding
the oocyte.
A) relaxin
B) hyaluronidase
C) calcium
D) zonal inhibiting proteins
E) glucose

B) hyaluronidase

13) Fertilization stimulates the oocyte to enter meiosis II and the fertilized oocyte is called a(n)
A) oogonium.
B) primary oocyte.
C) secondary oocyte.
D) ovum.
E) polar body.

D) ovum.

14) The developmental period that is the period of all embryological and early fetal development is
A) the first trimester.
B) the second trimester.
C) the third trimester.
D) infancy.
E) adolescence.

A) the first trimester.

15) The period of gestation that is characterized by rapid fetal growth and fat deposition is the ________ trimester.
A) first
B) second
C) third

C) third

16) The period of gestation when organs and organ systems complete most of their development
and the fetus looks distinctly human is the ________ trimester.
A) first
B) second
C) third

B) second

17) The term ________ refers to the time spent in prenatal development.
A) transformation
B) micturition
C) parturition
D) gestation
E) cleavage

D) gestation

18) The human gestation period consists of
A) fertilization and one trimester.
B) two trimesters of 1 month each.
C) three trimesters of 1 month each.
D) two trimesters of 2 months each.
E) three trimesters of 3 months each.

E) three trimesters of 3 months each.

19) Which of the following statements concerning development is false?
A) The term induction refers to the chemical interplay between developing cells.
B) The developing oocyte receives molecules that affect development from the surrounding granulosa cells.
C) Each blastomere in the blastocyst receives exactly the same cytoplasmic composition.
D) Differences in a cellʹs cytoplasmic makeup affect the cellʹs genetic activity.
E) Cells release molecules that affect the developmental process of neighboring cells.

C) Each blastomere in the blastocyst receives exactly the same cytoplasmic composition.

20) After fertilization, the first cell division is completed
A) within a few seconds.
B) within the hour.
C) about 6 hours later.
D) in 12 hours.
E) about 30 hours later.

E) about 30 hours later.

21) During early development, the Y chromosome produces a substance called ʺtestis determining factorʺ (TDF) that causes the indifferent gonad to become a testis. This would be an example of
A) capacitation.
B) activation.
C) differentiation.
D) induction.
E) predilection.

D) induction.

22) The process of cell division that divides the cytoplasm of the zygote among blastomeres is called
A) cleavage.
B) implantation.
C) placentation.
D) embryogenesis.
E) blastulation.

A) cleavage.

23) The penetration of the endometrium by the blastocyst is referred to as
A) cleavage.
B) implantation.
C) placentation.
D) embryogenesis.
E) fertilization.

B) implantation.

24) ________ are nearly identical cells that are produced by early cleavages.
A) Blastomeres
B) Morulas
C) Gastrulas
D) Amnions
E) Blastulas

A) Blastomeres

25) The solid ball of cells that has been likened to a mulberry is called a
A) chorion.
B) blastula.
C) gastrula.
D) morula.
E) blastocyst.

D) morula.

26) A blastocyst is a(n)
A) extraembryonic membrane.
B) solid ball of cells.
C) hollow ball of cells.
D) portion of the placenta.
E) origin of the urinary bladder.

C) hollow ball of cells.

27) The inner cell mass of the blastocyst will
A) form the placenta.
B) form the morula.
C) form the embryo.
D) form blood vessels of the placenta.
E) provide nutrients for early growth.

C) form the embryo.

28) During implantation, the
A) trophoblast erodes a path through the endometrium.
B) inner cell mass begins to form the placenta.
C) maternal blood vessels in the endometrium are walled off from the blastocyst.
D) entire trophoblast becomes syncytial.
E) inner cell mass is temporarily deprived of nutrients.

A) trophoblast erodes a path through the endometrium.

29) Under the influence of the trophoblast, maternal blood vessels in the endometrium
A) disappear.
B) attach to the inner cell mass.
C) break down and form sinuses or lacunae.
D) form a capillary network in the trophoblast.
E) increase in size and penetrate the blastocyst.

C) break down and form sinuses or lacunae.

30) A space opens within the inner cell mass that will form the
A) blastocoele.
B) lacunae.
C) amniotic cavity.
D) chorion.
E) allantois.

C) amniotic cavity.

31) Shortly after gastrulation, the body and organs of the embryo begin to form. This process is called
A) cleavage.
B) implantation.
C) placentation.
D) embryogenesis.
E) germination.

D) embryogenesis.

32) Which of the following is false concerning the allantois?
A) It derives partly from endoderm.
B) It projects into the umbilical cord.
C) It stores nitrogenous wastes.
D) Part will develop as the urinary bladder.
E) It acts as the fetal bone marrow.

E) It acts as the fetal bone marrow.

33) Ectoderm is to ________ as mesoderm is to ________.
A) neural tissue; muscle tissue
B) cardiovascular system; neural tissue
C) mesoderm; endoderm
D) neural tissue; epithelial tissue
E) muscle tissue; neural tissue

A) neural tissue; muscle tissue

34) The mesoderm and the trophoblast combine to form the
A) amnion.
B) amniotic sac.
C) chorion.
D) allantois.
E) inner cell mass.

C) chorion.

35) During gastrulation,
A) the blastomeres fuse.
B) the placenta penetrates the endometrium.
C) three germ layers are formed.
D) cells from the hypoblast move to the epiblast.
E) the neural tube closes.

C) three germ layers are formed.

36) The region known as the primitive streak is the site of
A) migration of mesodermal cells to form the endoderm.
B) endoderm formation.
C) ectoderm formation.
D) migration of ectodermal cells to form the mesoderm.
E) amnion formation.

D) migration of ectodermal cells to form the mesoderm.

37) The ectoderm forms
A) muscle.
B) blood.
C) neural tissues.
D) the lining of the digestive tract.
E) the urinary system.

C) neural tissues.

38) The mesoderm forms
A) muscle.
B) epidermis.
C) the brain.
D) the lining of the digestive tract.
E) respiratory epithelium.

A) muscle.

39) The endoderm forms
A) muscle.
B) blood.
C) neural tissue.
D) skin.
E) the urinary bladder.

E) the urinary bladder.

40) The extraembryonic membrane that forms blood is the
A) yolk sac.
B) amnion.
C) allantois.
D) chorion.
E) decidua.

A) yolk sac.

41) Oxygenated blood from the placenta returns to the fetus in the
A) allantois.
B) umbilical vein.
C) umbilical arteries.
D) decidua capsularis.
E) umbilical capillaries.

B) umbilical vein.

42) Where in the embryo does mesoderm first appear?
A) between the cell layers of the inner cell mass
B) within the blastocoele
C) in the chorionic villi
D) above the epiblast
E) around the trophoblast

A) between the cell layers of the inner cell mass

43) The part of the endometrium that covers the implanted embryo and lacks chorionic villi is the
A) parietal decidua.
B) albicans decidua.
C) functional decidua.
D) capsular decidua.
E) basal decidua.

D) capsular decidua.

44) Which embryonic germ layer forms the linings of the respiratory and digestive tracts?
A) mesoderm
B) ectoderm
C) trophoderm
D) endoderm
E) epiderm

D) endoderm

45) Which embryonic germ layer forms connective tissues such as bone and cartilage?
A) epiderm
B) trophoderm
C) ectoderm
D) mesooderm
E) endoderm

D) mesooderm

46) Which embryonic germ layer forms the brain and spinal cord?
A) ectoderm
B) endoderm
C) trophoderm
D) epiderm
E) mesooderm

A) ectoderm

47) The extraembryonic membrane that forms a fluid-filled sac is the
A) yolk sac.
B) amnion.
C) allantois.
D) chorion.
E) decidua.

B) amnion.

48) The umbilical cord contains the yolk sac, the placental blood vessels and the
A) chorionic villi.
B) allantois.
C) amnion.
D) chorion.
E) decidua.

B) allantois.

49) The extraembryonic membrane that forms the fetal portion of the placenta is the
A) yolk sac.
B) amnion.
C) allantois.
D) chorion.
E) decidua.

D) chorion.

50) Which of the following is not one of the extraembryonic membranes?
A) yolk sac
B) amnion
C) allantois
D) chorion
E) umbilical cord

E) umbilical cord

51) In ________, implantation occurs somewhere other than in the uterus.
A) ectopic pregnancy
B) hydramnios
C) placenta previa
D) abortion
E) spontaneous abortion

A) ectopic pregnancy

52) The outer layer of the blastocyst that can penetrate the endometrium is the
A) archegonium.
B) chorion.
C) gastrula.
D) blastula.
E) trophoblast.

E) trophoblast.

53) The hollow cavity within the blastocyst is the
A) blastula.
B) gastrula.
C) blastocoele.
D) trophoblast.
E) ootid.

C) blastocoele.

54) The ________ is the portion of the endometrium not in contact with the chorion.
A) trophoblast
B) allantois
C) capsular decidua
D) functional decidua
E) parietal decidua

E) parietal decidua

55) The ________ is formed by the allantois, blood vessels, and yolk sac.
A) umbilical cord
B) chorion
C) chorioallantoic membrane
D) trophoblast
E) amnion

A) umbilical cord

56) The almost identical cells produced by cleavage divisions are called
A) centromeres.
B) blastomeres.
C) telomeres.
D) myosomes.
E) somal cells.

B) blastomeres.

57) The process by which a viable embryo is formed is called
A) embryogenesis.
B) organogenesis.
C) gametogenesis.
D) morphogenesis.
E) blastogenesis.

A) embryogenesis.

58) Placental functions are concentrated in a disc-shaped area in the endometrium called the
A) trophoblast.
B) allantois.
C) capsular decidua.
D) basal decidua.
E) parietal decidua.

D) basal decidua.

59) Blood flows from the fetus to the placenta through paired
A) umbilical vein.
B) iliac veins.
C) umbilical arteries.
D) uterine veins.
E) uterine arteries.

C) umbilical arteries.

60) The processes that occur in the pre-embryonic period are
A) cleavage and implantation.
B) cleavage and placentation.
C) implantation and placentation.
D) implantation and embryogenesis.
E) placentation and embryogenesis.

A) cleavage and implantation.

61) The processes that occur in the embryonic period are
A) cleavage and implantation.
B) cleavage and placentation.
C) implantation and placentation.
D) implantation and embryogenesis.
E) placentation and embryogenesis.

E) placentation and embryogenesis.

62) Which of the following statements about the first trimester is false?
A) The events that occur during the first trimester are very complex.
B) Only about 40 percent of conceptions survive the first trimester.
C) During this trimester, cleavage, implantation, placentation and embryogenesis occur.
D) The fetus gains the most weight during the first trimester.
E) It consists of 10 developmental weeks.

D) The fetus gains the most weight during the first trimester.

63) The inner cellular layer of trophoblast that remains intact inside the blastocyst is termed the
A) morula.
B) cytotrophoblast.
C) synctiotrophoblast.
D) lacunae.
E) amnion.

B) cytotrophoblast.

64) The uterine epithelium is broken down by the enzyme,
A) hyaluronidase.
B) acrosin.
C) urase.
D) proteoglycan.
E) relaxin.

A) hyaluronidase.

65) The uterine epithelium is broken down by which structure of the blastocyst?
A) allantois
B) cytotrophoblast
C) syncytiotrophoblast
D) blastocoele
E) amnion

C) syncytiotrophoblast

66) The separation between the inner cell mass and the trophoblast forms a fluid-filled chamber
called the
A) chorion.
B) yolk sac.
C) allantois.
D) amniotic cavity.
E) placenta.

D) amniotic cavity.

67) The embryo becomes a fetus at
A) the end of the first week.
B) the end of the second week.
C) the end of the eighth week.
D) the end of the second trimester.
E) the end of the third trimester.

C) the end of the eighth week.

68) The primary nutrient source for early embryonic development that later becomes an important
site for blood formation is the
A) amniotic fluid.
B) placenta.
C) basal decidua.
D) umbilical vein.
E) yolk sac.

E) yolk sac.

69) The epidermis and accessory structures of skin form from which germ layer?
A) endoderm
B) mesoderm
C) epiderm
D) ectoderm
E) trophoderm

D) ectoderm

81) During the second trimester, the mesoderm on the outer surface of the amnion contacts the mesoderm on the inner surface of the chorion and fuse to form the ________ membrane.
A) cervical
B) syncytial
C) amniochorionic
D) embryonic
E) umbilical

C) amniochorionic

82) By the end of gestation, maternal blood volume normally increases by almost ________
percent.
A) 20
B) 25
C) 50
D) 80
E) 100

C) 50

83) Which of the following does not occur during pregnancy?
A) A womanʹs respiratory rate and tidal volume increase.
B) Maternal blood volume increases.
C) Maternal nutrient requirements increase.
D) A womanʹs glomerular filtration rate increases.
E) A womanʹs bladder capacity increases.

E) A womanʹs bladder capacity increases.

84) The placenta is a source of all of the following hormones, except
A) hCG.
B) relaxin.
C) placental lactogen.
D) progesterone.
E) luteinizing hormone.

E) luteinizing hormone.

85) The hormone that increases the flexibility of the pubic symphysis during pregnancy is
A) luteinizing hormone.
B) progesterone.
C) human chorionic gonadotropin.
D) human placental lactogen.
E) relaxin.

E) relaxin.

86) If fertilization occurs, the ________ is maintained because the embryo secretes ________.
A) corpus albicans; human chorionic gonadotrophin
B) corpus luteum; luteinizing hormone
C) corpus cavernosum; human chorionic gonadotrophin
D) corpus luteum; human chorionic gonadotrophin
E) corpus albicans; placental prolactin

D) corpus luteum; human chorionic gonadotrophin

87) The hormone called the hormone of pregnancy, inhibiting uterine contractions, is
A) hCG.
B) relaxin.
C) placental lactogen.
D) progesterone.
E) luteinizing hormone.

D) progesterone.

88) Mammary gland development requires a combination of all of the following hormones, except
A) oxytocin.
B) placental prolactin.
C) prolactin.
D) human placental lactogen.
E) estrogen.

A) oxytocin.

89) The prostaglandins produced in the endometrium
A) initiate the release of oxytocin for parturition.
B) stimulate smooth muscle contractions.
C) initiate secretory activity in the mammary glands.
D) promote breast development.
E) stimulate the milk let-down reflex.

B) stimulate smooth muscle contractions.

90) Stretching of the cervix causes an increase in the blood levels of
A) estrogen.
B) progesterone.
C) oxytocin.
D) relaxin.
E) chorionic gonadotropin.

C) oxytocin.

91) During gestation, contraction of the myometrium is inhibited by ________, produced by the corpus luteum.
A) progesterone
B) estrogen
C) oxytocin
D) prostaglandins
E) inhibin

A) progesterone

92) The first stage of labor is the ________ stage.
A) dilation
B) expulsion
C) placental
D) decidual
E) neonate

A) dilation

93) The stage of labor during which the fetus emerges from the vagina is called the ________ stage.
A) emergence
B) dilation
C) placental
D) expulsion
E) fetal

D) expulsion

94) An infant born ________ prematurely has a good chance of survival.
A) 1.5 months
B) 3 months
C) 4 months
D) 5 months
E) 6 months

A) 1.5 months

95) Uterine contractions that are irregular and brief that occur toward the end of gestation are called
A) parturition.
B) expulsion.
C) true labor.
D) Braxton-Hicks.
E) dilation.

D) Braxton-Hicks.

96) In a(n) ________, an incision is made in the perineal musculature.
A) episiotomy
B) lumbar puncture
C) crowning
D) epidural
E) peritoneal cut

A) episiotomy

97) Fraternal twins result from
A) one egg that is fertilized by two different sperm.
B) two different zygotes.
C) one zygote that splits into two zygotes.
D) two eggs fertilized by one sperm cell.
E) a blastula that splits into two blastulas.

B) two different zygotes.

98) Twins that occur when blastomeres separate are called
A) monozygotic.
B) blastulatory.
C) zygoblastic.
D) dizygotic.
E) fraternal.

A) monozygotic.

99) The goal of labor is childbirth, also termed
A) gestation.
B) development.
C) parturition.
D) abortion.
E) senescence.

C) parturition.

100) Which of the following places the stages of labor in the correct order?
A) placental, expulsion, dilation
B) placental, dilation, expulsion
C) expulsion, dilation, placental
D) dilation, placental, expulsion
E) dilation, expulsion, placental

E) dilation, expulsion, placental

101) Immediately after birth, a newbornʹs health is assessed by an Apgar score. Which of the
following is not part of the Apgar assessment?
A) heart rate
B) breathing
C) muscle tone
D) hearing
E) skin color

D) hearing

102) Which of the following does not occur at puberty?
A) FSH levels rise.
B) GnRH levels decline.
C) Levels of sex hormones rise.
D) Gametogenesis begins.
E) Secondary sexual characteristics begin to develop.

B) GnRH levels decline.

103) As a person ages,
A) the skin becomes more elastic.
B) lung tissue becomes more elastic.
C) peristalsis and muscle tone decrease.
D) all hormone levels decrease.
E) peristalsis and muscle tone decrease and some hormone levels decrease.

E) peristalsis and muscle tone decrease and some hormone levels decrease.

104) The infancy stage of life is considered to be over at
A) 3 months
B) age 2.
C) 6 months.
D) 1 month.
E) 18 months.

B) age 2.

105) ________ is the medical specialty that focuses on postnatal development from infancy to
adolescence.
A) Geriatrics
B) Orthopedics
C) Pediatrics
D) Psychiatrics
E) Obstetrics

C) Pediatrics

106) The neonatal period extends
A) for the first 24 hours of life.
B) for the first month of life.
C) until the first birthday.
D) for the first six months.
E) until breast feeding stops.

B) for the first month of life.

107) The developmental period heralded by the onset of puberty is known as
A) post-infancy.
B) adolescence.
C) early childhood.
D) teenage years.
E) pre-teen.

B) adolescence.

108) The period from 1 month after birth to 1 year is known as
A) childhood.
B) post-fetal.
C) neogen.
D) infancy.
E) neonatal.

D) infancy.

109) A mother has a lot of milk stored in the breast and mammary glands but cannot seem to expel the milk for her newborn. Her doctor thinks that the cause may be
A) low levels of oxytocin.
B) high levels of HCG.
C) low levels of estrogen.
D) low levels of progesterone.
E) unresponsive smooth muscle around the mammary glands.

A) low levels of oxytocin.

110) The clear liquid secreted by the mammary glands before milk production begins is called
A) milk.
B) colostrum.
C) serum.
D) plasma.
E) peritoneal.

B) colostrum.

111) Adolescence begins at the period of sexual maturity called
A) menopause.
B) puberty.
C) senescence.
D) postnatal.
E) gestation.

B) puberty.

112) All of the following changes occur during puberty, except
A) the hypothalamus decreases its production of GnRH.
B) FSH levels increase.
C) LH levels increase.
D) growth rate increases.
E) gamete formation begins.

A) the hypothalamus decreases its production of GnRH.

113) A patient comes in the clinic expressing concern over changes in her body. She says she has been experiencing axillary and genital hair growth, breast growth, acne and she is going through a growth spurt. You reassure her these are all a normal part of maturation and inform her that she has begun
A) menarche.
B) menopause.
C) peri-menopause.
D) prenatal development.
E) puberty.

E) puberty.

114) Non-sex chromosomes are called
A) homologous.
B) homozygous.
C) heterozygous.
D) autosomal.
E) chromatids.

D) autosomal.

115) The alternate forms of any one gene are called
A) homologous.
B) homozygous.
C) heterozygous.
D) autosomes.
E) alleles.

E) alleles.

116) If an individual carries a pair of alleles that are the same, the individual is ________ for the trait.
A) homologous
B) homozygous
C) heterozygous
D) autosomous
E) polygenic

B) homozygous

117) If a color-blind (X-linked recessive trait) man marries a woman who is heterozygous for the trait, what proportion of their male offspring can be expected to be color blind?
A) 1/2
B) 1/4
C) 1/8
D) 3/4
E) 100 (all)

A) 1/2

118) If an individual carries two different alleles for the same trait, the individual is ________ for the trait.
A) homologous
B) homozygous
C) heterozygous
D) autosomous
E) polygenic

C) heterozygous

119) If a sperm carrying the ʺYʺ chromosome fertilizes the ovum, the resulting offspring will be
A) haploid.
B) Rh positive blood type.
C) male.
D) fraternal twins.
E) female.

C) male.

120) The presence of a recessive gene can be detected (seen) only if the individual is
A) homozygous recessive.
B) heterozygous dominant.
C) heterozygous recessive.
D) homozygous dominant.
E) epistatic recessive.

A) homozygous recessive.

121) A woman who is heterozygous for blood type A mates with a man who is homozygous for blood type O. What blood type(s) would their children have?
A) 75% heterozygous type A
B) 100% type A
C) 75% homozygous type O
D) 100% type O
E) 50% type A, 50% type O

E) 50% type A, 50% type O

122) The gene for normal skin pigment (A) can also code for the recessive trait of albinism (a). An albino man and a homozygous normal pigmented woman marry and have four children. What is the phenotype of the children?
A) 75% normal skin pigment and 25% albino
B) 100% normal skin pigment
C) 50% normal skin pigment and 50% albino
D) 25% normal skin pigment and 75% albino
E) 100% albino

B) 100% normal skin pigment

123) In simple autosomal inheritance, phenotypic characters are determined, or controlled, by
A) a single pair of alleles.
B) multiple alleles.
C) the action of a single gene.
D) regulator genes on a different chromosome.
E) the genes on the Y chromosome.

A) a single pair of alleles.

124) In polygenic inheritance, phenotypic characters are
A) determined by a double pair of alleles.
B) determined by interactions among several genes.
C) determined by multiple copies of a single gene.
D) always controlled by genes on the same chromosome.
E) determined by the genes on the Y chromosome.

B) determined by interactions among several genes.

125) How many chromosomes do human gametes contain?
A) 12
B) 23
C) 46
D) 92
E) 6

B) 23

126) How many chromosomes do human somatic cells contain?
A) 12
B) 23
C) 46
D) 92
E) 6

C) 46

127) The 23rd set of chromosomes determines
A) characteristics of the brain.
B) sex.
C) body characteristics.
D) blood type.
E) sex drive.

B) sex.

128) In ________, a sample of amniotic fluid is removed and the fetal cells it contains are analyzed.
A) chorionic villus sampling
B) amniocentesis
C) paracentesis
D) amniosis
E) thoracentesis

B) amniocentesis

129) The full set of genetic information in an individualʹs chromosomes is called
A) pleiotype.
B) allotype.
C) phenotype.
D) isotype.
E) genome.

E) genome.

130) The traits of an individual controlled by his or her genotype are his or her
A) pleiotype.
B) allotype.
C) phenotype.
D) isotype.
E) genotype.

C) phenotype.

131) A ________ allele will always be expressed regardless of what the other allele happens to be.
A) homologous
B) homocentric
C) recessive
D) maternal
E) dominant

E) dominant

132) A ________ allele is expressed only when homozygous.
A) homologous
B) homocentric
C) recessive
D) maternal
E) dominant

C) recessive

133) The entire set of chromosomes of an individual can be visualized on a
A) locus.
B) map.
C) karyotype.
D) Punnett square.
E) genotype.

C) karyotype.

134) Height is not expressed by a simple dominant and recessive allele. This type of inheritance is termed
A) polygenic inheritance.
B) incomplete dominance.
C) codominance.
D) strict dominance.
E) simple inheritance.

A) polygenic inheritance.

135) The ABO blood type is an example of which type of inheritance?
A) polygenic inheritance
B) incomplete dominance
C) codominance
D) strict dominance
E) sex-linked

C) codominance

136) An individualʹs karyotype shows trisomy 21. This is an example of a
A) translocation.
B) chromosomal abnormality.
C) mutation.
D) recombination error.
E) teratogen.

B) chromosomal abnormality.

137) A geneʹs position on a chromosome is called a
A) karyotype.
B) map.
C) recombinant.
D) genome.
E) locus.

E) locus.

1) What is the name and function of the outer cell layer of a blastocyst?
A) inner cell mass; become the yolk sac
B) morula; become the amniotic fluid
C) trophoblast; provide nutrients
D) blastomere; implant into the uterine wall
E) blastocoele; form the embryo

C) trophoblast; provide nutrients

2) What is the name of the third germ layer that forms during gastrulation?
A) ectoderm
B) endoderm
C) mesoderm
D) primitive streak
E) embryonic disc

C) mesoderm

3) What hormones stimulate and increase the excitability of the myometrium?
A) oxytocin and prostaglandins
B) prolactin and prostaglandins
C) estrogen and progesterone
D) oxytocin and progesterone
E) estrogen and prostaglandins

A) oxytocin and prostaglandins

4) Explain why this is a karyotype of a male and not a female.
A) The 23rd pair of chromosomes are an XX.
B) The 23rd pair of chromosomes are an XY.
C) There are 24 pairs of chromosomes.
D) There are 22 pairs of chromosomes.
E) The 23rd chromosome is a Y chromosome.

B) The 23rd pair of chromosomes are an XY.

5) What types of inheritance are involved in the following phenotypes-nearsightedness, normal vision, and red-green color blindness?
A) simple inheritance; polygenic inheritance; sex-linked inheritance
B) polygenic inheritance; sex-linked inheritance; sex-linked inheritance
C) sex-linked inheritance; polygenic inheritance; polygenic inheritance
D) polygenic inheritance; simple inheritance; polygenic inheritance
E) simple inheritance; simple inheritance; sex-linked inheritance

E) simple inheritance; simple inheritance; sex-linked inheritance