Development and Aging - Chapter 18 Flashcards
Where are the mitochondria located in the sperm?
Nucleus
Middle piece
Head
Tail
Cell membrane
Middle piece
*Mitochondria are located in the middle piece of the sperm.
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.
All of the answer choices are associated with the egg.
*All of the answer choices are associated with the egg.
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
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.
In the “Divide” stage, cells begin the [____________] phase, when cells split in two over and over again.
Cleavage
Placenta
Placental
Cleavage
The [______________] is an organ that only appears during pregnancy and is created by the melding of the maternal and embryonic tissues.
Clevage
Placenta
Placental
Placenta
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
Placental
Which of these is associated with pre-embryonic development?
Primary germ layers
Embryonic disk
Morula
Formation of the umbilical cord
Gastrulation
Morula
*The morula, a ball of cells, forms early during pre-embryonic development.
The names of the extraembryonic membranes are derived from their function in animals that produce shelled eggs.
True
False
True
*The names of these membranes are derived from their functions in birds.
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
When it forms the gastrula
*Gastrulation involves morphogenesis and the formation of three germ layers.
The nervous system is to the ectoderm as the skeleton is to the
Mesoderm.
Blastula.
Endoderm.
Allantois.
Chorion.
Mesoderm
*The nervous system develops from ectoderm and the skeleton develops from the mesoderm.
When does the heart begin to develop?
Week 1
Week 5
Week 3
Week 7
Week 9
Week 3
*The heart begins to develop in the third week and continues into the fourth week.
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
Nose, eyes and ears become noticeable
*Nose, eyes, and ears are noticeable at about the 5th week.
At the end of the embryonic period, the embryo is about 12 inches long.
True
False
False
*At the end of the embryonic period, the embryo is approximately 1.5 inches long.
Embryonic development begins with
Fertilization.
Gastrulation.
The first cell division.
The development of the blastocyst.
Implantation.
Implantation
*Embryonic development begins at implantation.
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
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.
The blood of the mother and the fetus mix in the placenta.
True
False
False
*The blood of the mother and the fetus never mix because exchange takes place across the villi.
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.
They both carry oxygen-rich blood.
* Both the umbilical vein and the pulmonary veins carry oxygen-rich blood (which is unusual for veins).
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.
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.
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
Ductus arteriosus
*The ductus arteriosus enables the blood to bypass the lungs, and closes at birth.
Fetal development includes the third through ninth months of development.
True
False
True
*Fetal development follows embryonic development and lasts from the third through the ninth month of development.
The white, greasy, cheeselike substance that comers the fetus’s skin is called
Vernix caseosa.
Fontanel.
Foramen ovale.
Lanugo.
Ductus arteriosus.
Vernix caseosa
*The vernix caseosa is a white, greasy, cheeselike substance that probably protects the skin from the amnionic fluid.
The sex of an individual is determined at the moment of fertilization.
True
False
True
*Sex is determined by the chromosomal makeup (XX for females, XY for males), which is determined at the moment of fertilization.
Which of the following develops into male genital ducts?
Cloaca
Epididymis
Urogenital groove
Mullerian ducts
Wolffian ducts
Wolffian ducts
*The male genital ducts develop from the Wolffian ducts.
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.
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.