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

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

Answer 2

True

Question 3

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

Answer 3

False

Question 4

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 5

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

Question 6

The placenta begins to form after week 8.

Question 7

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

Question 8

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

Question 9

During implantation, the embryoblast undergoes gastrulation.

Question 10

Which of these 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

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

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

Question 13

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

Question 14

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 15

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

Question 16

Teratogens usually do not cause congenital anomalies.

Question 17

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 18

The chorion forms the fetal part of the placenta.

Question 19

Premature infants suffer especially from multiple dysfunctions resulting from inadequate liver
function.

Question 20

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

Question 21

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 22

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 23

Primary germ layers are formed during

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

Question 24

The spheroidal stage of early prenatal development with about 16 to 64 cells is called a/an

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

Question 25

Prior to ejaculation, in the sperm plasma membrane 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 26

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

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

Question 27

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 28

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

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

Question 29

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

A)30
B)300
C)3,000
D)30,000
E)300,000

Question 30

Twins produced when a single egg is fertilized are called twins, and 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 31

This figure shows the placenta and embryonic membranes.What does "1" represent?

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

Question 32

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 33

In fetal circulation, blood bypasses the lungs by flowing through

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

Question 34

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 35

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 36

The first body cavity is called the

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

Question 37

These are derivatives of ectoderm except

A)the salivary glands.
B)the nervous system.
C)the epidermis.
D)the cutaneous glands.
E)the dermis.

Question 38

By the time the conceptus arrives in the uterus,

A)it is still a zygote.
B)it is called a trophoblast.
C)it has the three primary germ layers.
D)it shows traces of all the organ systems.
E)it consists of 16 or more cells.

Question 39

This figure shows the placenta and embryonic membranes.What does "1" represent?

A)a maternal vein
B)a maternal artery
C)an umbilical vein
D)an umbilical artery
E)a placental sinus

Question 40

During implantation, the trophoblast divides into a deep layer, the , composed of individual cells, and a superficial layer, the , composed of a multinucleate mass of cytoplasm.

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

Question 41

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 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

The observation that there is a limit to how many times a cell can divide is the basis for the

A)autoimmune theory of senescence.
B)free radical theory of senescence.
C)cross-linking theory of senescence.
D)replicative senescence theory.
E)abortive theory of senescence.

Question 44

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

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

Question 45

These are have potentially teratogenic effects except

A)smoking.
B)alcohol.
C)infectious diseases.
D)sunlight.
E)X-rays.

Question 46

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

A)muscular
B)integumentary
C)respiratory
D)circulatory
E)nervous

Question 47

The embryonic membranes include all of the following except the

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

Question 48

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 49

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)spanking him/her.

Question 50

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

A)muscular
B)integumentary
C)skeletal
D)circulatory
E)nervous

Question 51

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 52

pass(es) from the maternal blood to the fetal blood; while 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 53

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 54

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 55

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 56

The first 6 weeks of postpartum life constitute

A)the transitional period.
B)the premature period.
C)the neonatal period.
D)senescence.
E)infancy.

Question 57

A teratogen is most likely to cause

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

Question 58

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 59

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 60

Muscular weakness tends to develop in old age for all of the following reasons except

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.
E)myocytes do not synthesize myosin anymore.

Question 61

Congenital anomalies can result from all of the following except

A)an 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 62

Senescence of the immune system makes older people more subject 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.