Development and Aging - Chapter 18

Question 1

Where are the mitochondria located in the sperm?

Nucleus

Middle piece

Head

Tail

Cell membrane

Answer 1

Middle piece

*Mitochondria are located in the middle piece of the sperm.

Question 2

Which of the following is associated with the egg?

Fertilization membrane

Zona Pellucida

Corona Radiata

Cortical granule

All of the answer choices are associated with the egg.

Answer 2

All of the answer choices are associated with the egg.

*All of the answer choices are associated with the egg.

Question 3

Which of the following is involved in the prevention of polyspermy?

Fusion of the sperm and egg nucleus

Acrosome of the sperm

Depolarization of the egg’s plasma membrane

Changes within the corona radiata

The number of chromosomes contained within the sperm

Answer 3

Depolarization of the egg’s plasma membrane

*As soon as a sperm touches and egg, the egg’s plasma membrane depolarizes. This prevents the binding of any other sperm.

Question 4

In the “Divide” stage, cells begin the [____________] phase, when cells split in two over and over again.

Cleavage

Placenta

Placental

Answer 4

Cleavage

Question 5

The [______________] is an organ that only appears during pregnancy and is created by the melding of the maternal and embryonic tissues.

Clevage

Placenta

Placental

Answer 5

Placenta

Question 6

After the expulsion stage of delivery, the so-called “afterbirth” is removed from the uterine wall in a stage called the [_________] stage.

Cleavage

Placenta

Placental

Answer 6

Placental

Question 7

Which of these is associated with pre-embryonic development?

Primary germ layers

Embryonic disk

Morula

Formation of the umbilical cord

Gastrulation

Answer 7

Morula

*The morula, a ball of cells, forms early during pre-embryonic development.

Question 8

The names of the extraembryonic membranes are derived from their function in animals that produce shelled eggs.

True

False

Answer 8

True

*The names of these membranes are derived from their functions in birds.

Question 9

At what point during development does the embryo form three germ layers?

When it forms the inner cell mass

When it begins cleavage

When it forms the gastrula

When the nervous system develops

When it becomes recognizable as human

Answer 9

When it forms the gastrula

*Gastrulation involves morphogenesis and the formation of three germ layers.

Question 10

The nervous system is to the ectoderm as the skeleton is to the

Mesoderm.

Blastula.

Endoderm.

Allantois.

Chorion.

Answer 10

Mesoderm

*The nervous system develops from ectoderm and the skeleton develops from the mesoderm.

Question 11

When does the heart begin to develop?

Week 1

Week 5

Week 3

Week 7

Week 9

Answer 11

Week 3

*The heart begins to develop in the third week and continues into the fourth week.

Question 12

Which of the following occurs during the embryonic stage of development?

Chorion appear

Testes descend into the scrotum

Heartbeat can be heard

Nose, eyes, and ears become noticeable

Fingernails appear

Answer 12

Nose, eyes and ears become noticeable

*Nose, eyes, and ears are noticeable at about the 5th week.

Question 13

At the end of the embryonic period, the embryo is about 12 inches long.

True

False

Answer 13

False

*At the end of the embryonic period, the embryo is approximately 1.5 inches long.

Question 14

Embryonic development begins with

Fertilization.

Gastrulation.

The first cell division.

The development of the blastocyst.

Implantation.

Answer 14

Implantation

*Embryonic development begins at implantation.

Question 15

The nervous system develops enough to permit reflex actions during which period of development?

Fetal, months 3-4

Embryonic, weeks 4-5

Embryonic, weeks 2-3

Pre-embryonic

Embryonic, weeks 6-8

Answer 15

Embryonic, weeks 6-8

*At 6-8 weeks, the nervous system is developed well enough to permit reflex actions. During the pre-embryonic stage there is no nervous system. During the embryobic weeks 2-3 and weeks 3-4, the nervous system is not developed enough to permit the reflex actions.

Question 16

The blood of the mother and the fetus mix in the placenta.

True

False

Answer 16

False

*The blood of the mother and the fetus never mix because exchange takes place across the villi.

Question 17

How are the pulmonary veins and the umbilical veins similar?

They both carry blood to the lungs.

They both connect to the superior vena cava.

They both connect to the placenta.

They both carry oxygen-rich blood.

They are both present in an adult human.

Answer 17

They both carry oxygen-rich blood.

* Both the umbilical vein and the pulmonary veins carry oxygen-rich blood (which is unusual for veins).

Question 18

The umbilical arteries carry

Oxygen-rich blood to the mother.

Oxygen-poor blood to the placenta.

Oxygen-rich blood to the placenta.

Oxygen-rich blood to the developing fetus.

Oxygen-poor blood to the developing fetus.

Answer 18

Oxygen-poor blood to the placenta.

*The umbilical arteries carry oxygen-poor blood to the placenta. The umbilical veins carry the oxygen-rich blood to the fetus.

Question 19

Which of the following is present in the fetus but not in an adult human?

Superior vena cava

Ductus Arteriosus

Left atrium

Internal iliac artery

Pulmonary vein

Answer 19

Ductus arteriosus

*The ductus arteriosus enables the blood to bypass the lungs, and closes at birth.

Question 20

Fetal development includes the third through ninth months of development.

True

False

Answer 20

True

*Fetal development follows embryonic development and lasts from the third through the ninth month of development.

Question 21

The white, greasy, cheeselike substance that comers the fetus’s skin is called

Vernix caseosa.

Fontanel.

Foramen ovale.

Lanugo.

Ductus arteriosus.

Answer 21

Vernix caseosa

*The vernix caseosa is a white, greasy, cheeselike substance that probably protects the skin from the amnionic fluid.

Question 22

The sex of an individual is determined at the moment of fertilization.

True

False

Answer 22

True

*Sex is determined by the chromosomal makeup (XX for females, XY for males), which is determined at the moment of fertilization.

Question 23

Which of the following develops into male genital ducts?

Cloaca

Epididymis

Urogenital groove

Mullerian ducts

Wolffian ducts

Answer 23

Wolffian ducts

*The male genital ducts develop from the Wolffian ducts.

Question 24

If a fetus contains an X and a Y chromosome but a defective SRY gene, they will develop

Into an anatomical male because testosterone is present.

Into an anatomical female because testosterone is not present.

Into a hermaphrodite due to the presence of estrogen and testosterone.

Into an anatomical male because testosterone is not present.

Into an anatomical female because testosterone is present.

Answer 24

Into an anatomical female because testosterone is not present.

*A defective SRY gene would not allow the production of testosterone and the fetus would develop into a female.

Question 25

Which of the following is an effect of progesterone?

Low blood pressure

Relaxation of smooth muscle

Reduced uterine motility

Reduced maternal immune response to the fetus

All of the answer choices are effects of progesterone.

Answer 25

All of the answer choices are effects of progesterone.

*All of the answer choices are effects of progesterone.

Question 26

Which of the following problems is associated with pregnancy?

Lordosis

Gastrointestinal reflux

Lower back pain

Incontinence

All of the answer choices are problems associated with pregnancy.

Answer 26

All of the answer choices are problems associated with pregnancy.

*All of the answer choices are problems associated with pregnancy.

Question 27

Which of the following occurs prior to or during stage 1 of labor?

Effacement

Uterine contractions

Breaking water

Bloody show

All of the answer choices happen prior to or during stage I of labor.

Answer 27

All of the answer choices happen prior or during stage I of labor.

Question 28

The oldest person to have ever lived on record was [_____________] years old.

122

Telomeres

Decrease

Answer 28

122

Question 29

Chromosomes have protective regions at the ends called [____________] that shorten every time they replicate.

122

Telomeres

Decrease

Answer 29

Telomeres

Question 30

As we get older, stem cells [________] in number.

122

Telomeres

Decrease

Answer 30

Decrease

Question 31

Which hypothesis of aging involves mitochondria?

Extrinsic factors

External factors

Gene damage by free radicals

Whole-body process

Damage accumulation

Answer 31

Gene damage by free radicals

*The current mitochondrial hypothesis of aging suggests that aging may be due to damage of DNA by free radicals.

Question 32

Which of the following skin changes is associated with growing older?

The number of elastic fibers decreases.

There are fewer sweat glands for sweating to occur.

Pigmented blotches appear on the skin.

There is less adipose tissue in the subcutaneous layer.

All of the answer choices are changes in the skin associated with growing older.

Answer 32

All of the answer choices are changes in the skin associated with growing older.

*All of the answer choices are changes in the skin associated with growing older.

Question 33

Which of the following statements is related to a decrease in blood flow?

Males become infertile.

Females undergo menopause.

The liver does not metabolize drugs as efficiently as before.

The homeostatic adjustment to heat is limited.

Ventilation of the lungs is reduced.

Answer 33

The liver does not metabolize drugs as efficiently as before.

*As the blood flow to the liver is reduced, the liver does not metabolize drugs as efficiently as before.

Question 34

The number of neural cells in the cerebral cortex decreases during the aging process.

True

False

Answer 34

True

Neural cells are lost due to a decrease in oxygen availability. As blood vessels narrow, blood flow will be reduced, decreasing the available oxygen.

Question 35

How do males and females differ as they age?

Males lose skeletal muscle mass, but females tend to gain muscle mass.

Males develop urinary incontinence, but females don’t.

Males can continue to produce sperm until death, but females do not produce eggs past menopause.

Females undergo menopause, but males do not undergo any changes in their reproductive hormone levels.

Females dehydrate faster than males do.

Answer 35

Males can continue to produce sperm until death, but females do not continue to produce eggs.

*Males can continue to produce sperm until death, but females do not produce eggs past menopause.

Question 36

Why would you predict that the blood carbon dioxide levels in a pregnant woman would fall?

The bronchial tubes relax.

She has trouble breathing due to the expanding uterus.

The maternal oxygen levels are also falling.

The fetus is removing carbon dioxide from her blood.

Pregnancy creates a favorable concentration gradient between the fetal and maternal blood.

Answer 36

Pregnancy creates a favorable concentration gradient between the fetal and maternal blood.

*A favorable concentration gradient allows carbon dioxide to flow from the fetal blood into the maternal blood at the placenta.

Question 37

What occurs during stage 3 of labor?

Effacement occurs.

The cervix dilates.

The placenta is expelled.

The amnionic sac ruptures.

The baby is born.

Answer 37

The placenta is expelled.

*The afterbirth is expelled during the third stage of birth.

Question 38

The first system in the body to become visibly differentiated during development is the

Reproductive system.

Cardiovascular system.

Respiratory system.

Nervous system.

Digestive system.

Answer 38

Nervous system.

*The nervous system is the first system to become visibly differentiated.

Question 39

During fertilization, several sperm penetrate the corona radiata.

True

False

Answer 39

True

*Several sperm do penetrate the corona radiata, but only one penetrates the zona pellucida.

Question 40

The ____________ is the first embryonic membrane to appear, and it is the first site of ___________.

Chorion; neural system development

Yolk sac; blood cell formation

Amnion; umbilical cord formation

Allantois; amnionic fluid formation

Yolk sac; placental development

Answer 40

Yolk sac; blood cell formation

*The yolk sac is the first embryonic membrane to appear and it is the first site of blood cell formation.

Question 41

The yolk sac of the chick provides nutrients to the developing embryo. What structure serves the same role in humans?

Allantois

Zona pellucida

Amnion

Yolk sac

Chorion

Answer 41

Chorion

*The chorion develops into the fetal half of the placenta and provides the embryo with nourishment and oxygen. The allantois develops into the umbilical arteries and veins. The yolk sac contains food for the developing embryo. The amnion contains protective fluid that cushions the embryo. The zona pellucida is the surrounding membrane of the egg prior to fertilization.

Question 42

What structure produces progesterone and estrogen during pregnancy?

Hypothalamus

Placenta

Ovaries

Anterior pituitary

Posterior pituitary

Answer 42

Placenta

*The placenta is the source of progesterone and estrogen during pregnancy.

Question 43

The amnion is to the amniotic fluid as the allantois is to the

Blood cell precursors.

Umbilical blood vessels.

Yolk.

Amnionic cavity.

Chorionic villi.

Answer 43

Umbilical blood vessels.

*The amnion contains the amnionic fluid while the allantois contains the umbilical blood vessels.

Question 44

When cells take on a specific structure and function, this is called

Growth.

Morphogenesis.

Cleavage.

Fertilization.

Differentiation.

Answer 44

Differentiation

*Differentiation occurs when cells take on a specific structure and function. Cleavage is when the zygote begins to divide. Growth is the increase in the size of the cells. Morphogenesis is the shaping of the embryo. Fertilization is the union of the sperm and egg to form the embryo.