chapter 18
When does the mother first begin to feel the fetus move?
5-7 months
Which of the following is not true concerning the fetus during the third month of development?
Bone begins to be replaced with cartilage in certain areas of the skeleton.
How do males and females differ as they age?
Males can continue to produce sperm until death but females do not continue to produce eggs.
Does a woman ovulate during pregnancy? Why or why not?
No, because negative feedback on the hypothalamus prevents new follicles from maturing.
Which of the following occurs during the embryonic stage of development?
Nose, eyes, and ear become noticeable.
Why would you predict that the blood carbon dioxide levels in a pregnant woman would fall?
Pregnancy creates a favorable concentration gradient between the fetal and maternal blood.
Which of the following statements is related to a decrease in blood flow?
The liver does not metabolize drugs as efficiently as before.
What occurs during stage 3 of labor?
The placenta is expelled.
Which of the following skin changes is not associated with growing older?
There is an increase in the number of oil glands.
How are the pulmonary veins and the umbilical veins similar?
They both carry oxygen-rich blood.
Which of the following develops into the male genital ducts?
Wolffian ducts
Which of the following is not associated with the egg?
acrosome
Which of the following is not involved in the increase in blood volume in a pregnant woman?
an increase in blood oxygen levels
The yolk sac of the chick provides nutrients to the developing embryo. What structure serves the same role in humans?
chorion
The adhering follicular cells that surround the egg are called the
corona radiata
Which of the following gives the correct order of layers the sperm crosses when entering the egg?
corona radiata, zona pellucida, oocyte plasma membrane
Which of the following is involved in the prevention of polyspermy?
depolarization of the egg's plasma membrane
When cells take on specific structure and function, this is called
differentiation
Which of the following does not occur prior to or during stage 1 of labor?
dislodging of the placenta
Which of the following is present in the fetus but not in an adult human?
ductus arteriosus
Which of the following would be considered a poor health practice for a woman planning to get pregnant or already pregnant?
eating enough to feed two people
The nervous system develops enough to permit reflex actions during which period of development?
embryonic, weeks 6 - 8
T or F -- At the end of the embryonic period, the embryo is about 12 inches long.
false
T or F -- Development ceases at birth.
false
T or F -- Estrogen is responsible for the onset and continuation of labor.
false
T or F -- Most birth defects are due to the inheritance of an abnormal number of chromosomes.
false
T or F -- Once the cortical granules release their enzymes, the corona radiata becomes the fertilization membrane.
false
T or F -- The 4 cell stage of development is almost twice the size of the 2 cell stage of development.
false
T or F -- The blood of the mother and the fetus mix in the placenta.
false
T or F -- The embryonic disk becomes the inner cell mass after gastrulation.
false
T or F -- When the uterus begins to contract, it is almost time for the baby to be born.
false
Which hypothesis of aging involves mitochondria?
genetic in origin
Which part of the sperm contains the chromosomes?
head
Embryonic development begins with
implantation
Which of the following problems is not associated with pregnancy?
impotence
Which of the following is not a chief effect of progesterone?
increased uterine blood flow
If a fetus contains an X and a Y chromosome but a defective SRY gene, they will develop
into a female because testosterone is not present.
The nervous system is to the ectoderm as the skeleton is to the
mesoderm
Where are the mitochondria located in the sperm?
middle piece
When cells begin to move in the embryo in relation to other cells, this is called
morphogenesis.
Which of these is associated with pre-embryonic development?
morula
The first system in the body to become visibly differentiated during development is the
nervous system
The umbilical arteries carry
oxygen-poor blood to the placenta.
What structure produces progesterone and estrogen during pregnancy?
placenta
Which of the following defines "aging"?
progressive changes from infancy until death
When does the heart begin to develop?
three weeks
T or F -- During fertilization, several sperm penetrate the corona radiata.
true
T or F -- Fetal development includes the third through ninth months of development.
true
T or F -- Few neural cells in the cerebral cortex are lost during the normal aging process.
true
T or F -- The names of the extraembryonic membranes are derived from their function in animals that produce shelled eggs.
true
T or F -- The sex of an individual is determined at the moment of fertilization.
true
The amnion is to the amniotic fluid as the allantois is to the
umbilical blood vessels.
Which of the following is not derived from the endoderm?
urinary system
The white, greasy, cheeselike substance that covers the skin is called
vernix caseosa.
At what point during development does the embryo form three germ layers?
when it forms the gastrula
Y or N -- Sheila is experiencing contractions every 15 to 20 minutes that last for 40 seconds or longer. Is she ready to give birth?
yes
The _______ is the first embryonic membrane to appear, and it is the first site of ___________.
yolk sac, blood cell formation