Deck 29: Human Development and Aging

Question 1

The embryonic stage extends from 16 days through the end of week 8.

Answer 1

True

Question 2

Neonatal immunity depends on IgG and IgA acquired through the placenta and colostrum,respectively.

Answer 2

True

Question 3

Which of the folllowing lists the stages or structures of prenatal development in the correct order?

A) Cleavage,zygote,morula,blastocyst,embryo,fetus
B) Zygote,morula,blastocyst,cleavage,embryo,fetus
C) Zygote,cleavage,morula,blastocyst,embryo,fetus
D) Zygote,embryo,morula,blastocyst,cleavage,fetus
E) Embryo,zygote,blastocyst,cleavage,morula,fetus

Answer 3

C

Question 4

Teratogens usually do not cause congenital anomalies.

Question 5

The placenta begins to form after week 8.

Question 6

Cleavage results in daughter cells containing half the number of chromosomes of the parent cell.

Question 7

Sperm must travel to the distal end of the uterine tube to encounter the egg before it dies.

Question 8

A person in his or her 90's can increase muscle strength by two or three times with 40 minutes of isometric exercise per week.

Question 9

To some extent,the heat loss of the neonate is compensated for by the thermal insulation provided by brown fat.

Question 10

Life expectancy has steadily increased in the last century,whereas life span has not.

Question 11

The process that makes it possible for sperm to penetrate the egg is called __________.

A) sperm migration
B) capacitation
C) the cortical reaction
D) morulation
E) cleavage

Question 12

Senescence begins at different ages and progresses at different rates in different organ systems.

Question 13

During implantation,the embryoblast undergoes gastrulation.

Question 14

Trophoblastic nutrition refers to the nutrition of the conceptus before it implants.

Question 15

Inadequate liver function is the most common reason that premature infants suffer from multiple dysfunctions.

Question 16

In the slow block to polyspermy,sperm penetration releases an inflow of __________,which in turn stimulates the __________.

A) Cl^-;corona radiata
B) K⁺;zona pellucida
C) Na⁺;fertilization membrane
D) Ca²⁺;fertilization membrane
E) Ca²⁺;cortical reaction

Question 17

In the fast block to polyspermy,binding of sperm opens up __________ channels,which depolarizes the egg membrane and __________.

A) Na⁺;prevents the entrance of any more sperm
B) Na⁺;prevents the entrance of more Na⁺
C) Na⁺;prevents the entrance of Ca²⁺
D) Ca²⁺;prevents the entrance of any more sperm
E) Ca²⁺;prevents the entrance of more Na⁺

Question 18

The slow block refers to the mechanism that prevents fertilization of another egg when one is already pregnant.

Question 19

The fertilization membrane is the endometrial tissue that receives the conceptus.

Question 20

The chorion forms the fetal part of the placenta.

Question 21

Mesenchyme gives rise to __________.

A) nervous tissue
B) muscle,bone,and blood
C) digestive organs and endocrine glands
D) reproductive and urinary systems
E) the integumentary system and exocrine glands

Question 22

Out of the 300 million ejaculated sperm,only about __________ reach the vicinity of the egg.

A) 20 to 30
B) 200 to 300
C) 2000 to 3000
D) 20,000 to 30,000
E) half

Question 23

The optimal "window of opportunity" to conceive a child is __________.

A) a few days before ovulation to less than a day after
B) less than a day before ovulation to less than a day after
C) a few days before ovulation to a few days after
D) a few days before ovulation
E) a few days after ovulation

Question 24

The _________ begins to develop about 11 days after conception,and is the sole source of fetal nutrition from the end of week 12 until birth.

A) yolk sac
B) placenta
C) amnion
D) trophoblast
E) blastocyst

Question 25

As it implants,the conceptus is nourished by means of __________.

A) trophoblastic nutrition
B) uterine milk
C) nutrient diffusion from the endometrium
D) placenta
E) umbilical nutrition

Question 26

The __________ is an embryonic membrane that serves as the origin of the first blood and germ cells.

A) yolk sac
B) allantois
C) chorion
D) amnion
E) placenta

Question 27

The first body cavity is called the __________.

A) coelom
B) amniotic cavity
C) yolk sac
D) somite
E) chorion

Question 28

The spheroidal stage of early prenatal development with about 16 to 64 cells is called a(n)__________.

A) zygote
B) embryo
C) blastomere
D) morula
E) blastocyst

Question 29

The __________ encloses all the rest of the membranes and the embryo.

A) chorion
B) allantois
C) yolk sac
D) amnion
E) zona pellucida

Question 30

During implantation,the trophoblast divides into a deep layer called the _________,which is composed of individual cells.

A) chorion
B) amnion
C) syncytiotrophoblast
D) cytotrophoblast
E) embryoblast

Question 31

By the time the conceptus arrives in the uterus,it consists of at least __________ or more cells.

A) 2
B) 4
C) 8
D) 16
E) 32

Question 32

Regarding fertilization,which of the following events happens first?

A) Formation of a fertilization membrane
B) The fast block to polyspermy
C) The slow block to polyspermy
D) The cortical reaction
E) The acrosomal reaction

Question 33

Which of the following is not a derivative of ectoderm?

A) Salivary glands
B) The nervous system
C) The epidermis
D) Cutaneous glands
E) The dermis

Question 34

By the end of 8 weeks,the individual is considered a fetus because __________.

A) all the primary germ layers are formed
B) the amniotic cavity has formed
C) all of the organ systems are present
D) the neural tube and yolk sac have formed
E) the mesoderm has formed

Question 35

Prior to ejaculation,__________ in the plasma membrane of the sperm prevents premature release of __________.

A) cholesterol;acrosomal enzymes
B) protein;acrosomal enzymes
C) carbohydrates;prostaglandins
D) hyaluronic acid;prostaglandins
E) acrosin and hyaluronidase;acrosomal enzymes

Question 36

The __________ completely encloses the embryo and provides it with a stable environment.

A) yolk sac
B) amnion
C) chorion
D) chorionic villus
E) allantois

Question 37

In the blastocyst,the trophoblast will become __________,whereas the embryoblast will become __________.

A) part of the placenta;the yolk sac
B) part of the placenta;the embryo
C) the embryo;part of the placenta
D) the embryo;the yolk sac
E) the yolk sac;the embryo

Question 38

During implantation,the trophoblast divides into a superficial layer called the __________,which is composed of a multinucleate mass of cytoplasm.

A) chorion
B) embryoblast
C) amnion
D) syncytiotrophoblast
E) cytotrophoblast

Question 39

Primary germ layers are formed during __________

A) implantation
B) cleavage
C) conception
D) organogenesis
E) gastrulation

Question 40

Twins produced when a single egg is fertilized are called __________ twins.Twins produced from two eggs ovulated at the same time are called __________ twins.

A) monozygotic;identical
B) dizygotic;nonidentical
C) monozygotic;dizygotic
D) dizygotic;monozygotic
E) nonidentical;identical

Question 41

Which of the following does not have potentially teratogenic effects?

A) Smoking
B) Alcohol
C) Infectious diseases
D) Sunlight
E) X-rays

Question 42

Oxygenated blood reaches the fetus through the __________.

A) umbilical vein
B) umbilical arteries
C) maternal vein
D) maternal arteries
E) placental sinus

Question 43

A teratogen is most likely to cause __________.

A) a deformity of the limbs
B) aneuploidy
C) trisomy
D) nondisjunction
E) a mutation

Question 44

__________ pass(es)from the maternal blood to the fetal blood.Fetal __________ pass(es)the other way.

A) Carbon dioxide and oxygen;wastes
B) Carbon dioxide;nutrients
C) Wastes;nutrients and oxygen
D) Wastes and nutrients;oxygen and carbon dioxide
E) Oxygen and nutrients;wastes

Question 45

During birth,an infant is normally stimulated to breathe by __________.

A) CO₂ accumulating in the baby's blood
B) an increased O₂ level in the baby's new environment
C) prostaglandins
D) surfactant
E) being spanked by the doctor

Question 46

Which of the following organ systems shows the greatest anatomical change in the transitional period after birth?

A) Muscular system
B) Integumentary system
C) Skeletal system
D) Circulatory system
E) Nervous system

Question 47

Which of the following is not considered an embryonic membrane?

A) Yolk sac
B) Placenta
C) Allantois
D) Chorion
E) Amnion

Question 48

The first 6 weeks of postpartum life constitute the __________ period.

A) transitional
B) premature
C) neonatal
D) senescence
E) infancy

Question 49

Infant respiratory distress syndrome (IRDS)is caused by __________.

A) production of very thick respiratory mucus
B) deficiency of pulmonary surfactant
C) underdeveloped respiratory epithelium
D) pulmonary edema
E) overinflated alveoli

Question 50

The digital rays of a fetus give rise to __________.

A) arms and legs
B) ribs and intercostal muscles
C) fingers and toes
D) extensor digitorum muscles
E) radial muscles of the iris

Question 51

Urine retention is a greater problem for elderly men than for elderly women because men __________.

A) can develop benign prostatic hyperplasia
B) have larger bladders
C) have weaker urinary sphincters
D) have narrower ureters
E) have fewer glomeruli

Question 52

Only autosomal trisomies involving chromosomes 13,18,and 21 are survivable.Why would this be?

A) These are relatively short chromosomes.
B) These are relatively long chromosomes.
C) These are relatively gene-poor chromosomes.
D) These are redundant chromosomes.
E) These chromosomes have no genes.

Question 53

In fetal circulation,blood bypasses the lungs by flowing through the __________.

A) umbilical vein and umbilical arteries
B) fossa ovalis and umbilical arteries and vein
C) foramen ovale and ductus arteriosus
D) ductus venosus and ductus arteriosus
E) ligamentum venosum and ligamentum arteriosum

Question 54

Down syndrome (trisomy-21)results from _________.

A) a mutagen
B) nondisjunction
C) a teratogen
D) a sex-linked mutation
E) an autosomal recessive allele

Question 55

In fetal circulation,the __________ bypasses the liver and the __________ bypasses the lungs.

A) ligamentum venosum;ligamentum arteriosum
B) foramen ovale;ductus venosus
C) ductus arteriosus;ductus venosus
D) ductus venosus;ductus arteriosus
E) ligamentum arteriosum;foramen ovale

Question 56

Which of the following major events of prenatal development happens first?

A) The eyes are fully open
B) The body is covered with lanugo
C) Bone calcification begins
D) The central nervous system begins to form
E) Meconium accumulates in the intestines

Question 57

The fossa ovalis is a remnant of the __________ of the fetus.

A) ductus arteriosus
B) ductus venosus
C) umbilical artery
D) umbilical vein
E) foramen ovale

Question 58

Which of the following organ systems faces the greatest physiological challenge in the transitional period after birth?

A) Muscular system
B) Integumentary system
C) Respiratory system
D) Circulatory system
E) Nervous system

Question 59

Which of the following is not a reason muscular weakness tends to develop in old age?

A) Aged muscle has less glycogen,myoglobin,and creatine phosphate.
B) There are fewer motor neurons in the spinal cord.
C) Aged muscle fibers have fewer myofibrils.
D) There are fewer and smaller mitochondria in aged muscle.
E) The myocytes of aged muscle no longer synthesize myosin.

Question 60

The most likely outcome of nondisjunction is the production of a gamete receiving __________.

A) no chromosomes
B) 46 chromosomes
C) 44 chromosomes
D) 23 chromosomes
E) 22 chromosomes

Question 61

Which of the following systems shows the least overall senescence?

A) Muscular system
B) Endocrine system
C) Integumentary system
D) Reproductive system
E) Urinary system

Question 62

Which of the following statements is true regarding telomeres?

A) Telomeres are cytoplasmic enzymes involved in senescence.
B) Telomeres are antioxidants that slow the progress of senescence.
C) Telomeres are DNA segments at each end of a chromosome.
D) Telomeres are proteins that cap the ends of the chromosomes.
E) Telomeres are motor molecules that guide embryonic cells to the right destinations.

Question 63

Senescence of the immune system makes older people more susceptible to cancer and infectious disease because of a decline in __________.

A) alpha and beta globulins
B) red blood cells and platelets
C) complement proteins
D) prothrombin and fibrinogen
E) antigen-presenting cells and helper T cells

Question 64

Older people may require lower drug doses than younger people because __________.

A) their organs are more sensitive to drugs
B) they have lower rates of renal clearance
C) they do not absorb as much drug from the small intestine
D) there is less tissue mass to treat
E) a lifetime of mutations results in unpredictable drug reactions

Question 65

The fetus deposits fat in its subcutaneous tissue in the 7th month of gestation.

Question 66

Which of the following is not a known benefit of regular exercise?

A) Maintained joint mobility
B) Maintained strength
C) Decreased incidence of hypertension
D) Maintained endurance
E) Prolonged life expectancy

Question 67

Which of the following is not a known cause of congenital anomalies?

A) Infectious disease in the mother during pregnancy
B) A genetic disorder
C) Exposure to teratogens during pregnancy
D) Smoking during lactation
E) Smoking during pregnancy

Question 68

The observation that there is a limit to how many times a cell can divide is the basis for the __________ theory of senescence.

A) autoimmune
B) free radical
C) cross-linking
D) replicative
E) abortive