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Problem L2.1
The prenatal period typically lasts 38 weeks. From the clinical viewpoint, a pregnancy typically lasts 40 weeks. What is the reason for this difference?
Problem L2.2
Why is the single-celled zygote approximately the same size as the multicellular blastocyst before it implants in the uterine wall?
Problem L2.3
Why do most spontaneous abortions occur in the first trimester?
Problem L2.4
Explain why many pregnant women frequently feel the urge to urinate during their last trimester.
Problem L3.1
Ms. Noble is in the first trimester of her pregnancy when she suddenly feels severe pain in her lower abdomen. She rushes to the hospital where it is discovered that she has an ectopic pregnancy. The physician wants to do immediate surgery, but Ms. Noble argues that the embryo could simply move to the uterus if they wait. What would you tell this patient?
Problem L3.2
A new allergy medicine has just been approved by the Food and Drug Administration (FDA); however, it is not approved for pregnant women. What might be the reason for this exclusion?
Problem L3.3
Determine the probability of a couple having a child with a widow's peak if the conditions are as follows: The gene for widow's peak follows strict autosomal dominant-recessive inheritance. Widow's peak (W) is dominant, and no widow's peak (w) is recessive. The genotype of the mother is Ww, and the genotype of the father is ww.
Problem L3.4
Elise is a freshman college student taking Introduction to Biology. In lab, she is asked her parents' blood types to complete a Punnett square. She knows that she has type A blood and that her mother has type B, but she does not know her father's blood type. Elise's lab partner assures her that she can figure out her father's blood type just by knowing her own and her mother's. Is her lab partner correct? Explain why or why not.
Problem L3.5
Laura has diabetes and is 6 months pregnant. Lately, her blood pressure and blood glucose levels have been higher than normal. What factors related to the pregnancy might cause Laura's blood pressure and blood glucose to rise?
Problem 1
Match the correct time period of gestation with the prenatal period of development:
________Pre-embryonic period
________Fetal period
________Embryonic period
a. Weeks 3–8
b. Weeks 1–2
c. Weeks 9–38
Problem 2
During the pre-embryonic period, the conceptus divides into hundreds of cells by a process called ________ and becomes a/an ________, which implants in the uterine wall.
Problem 3a
Mark the following statements about fertilization as true or false. If a statement is false, correct it to make a true statement.
Fertilization is the fusion of a sperm and a secondary oocyte to form a new cell called a zygote.
Problem 3b
Mark the following statements about fertilization as true or false. If a statement is false, correct it to make a true statement.
Prostaglandins in semen may assist with the movement of sperm farther into the female reproductive tract by stimulating uterine contractions.
Problem 3c
Mark the following statements about fertilization as true or false. If a statement is false, correct it to make a true statement.
Secondary oocytes are covered with a layer of cells called the zona pellucida.
Problem 3d
Mark the following statements about fertilization as true or false. If a statement is false, correct it to make a true statement.
The cortical reaction allows additional sperm cells to bind to the oocyte.
Problem 4
Which of the following areas in the female reproductive tract is the site of fertilization?
a. Uterus
b. Ampulla of the uterine tube
c. Vagina
d. Cervix of the uterus
e. Any of these areas are possible sites of fertilization
Problem 5
Number the sequence of events in fertilization.
________ Formation of male and female pronuclei
________ Acrosomal reaction
________ Rejection of sperm
________ Binding of sperm cells
________ Cortical reaction
________ Fusion of pronuclei
Problem 6
The blastocyst has two distinct cell populations: large, flat cells called the ________ and a cluster of round cells called the ________.
Problem 7
Match the extraembryonic membrane with the correct statement:
Amnion
Yolk sac
Allantois
Chorion
a. Forms part of the digestive tract and is the first extraembryonic membrane to form
b. Forms the base for the umbilical cord and later becomes part of the urinary bladder
c. Encloses the conceptus and secretes fluid to fill the sac
d. Forms outgrowths that blend with the stratum functional layer of the uterus
Problem 8
_____+ is the process of forming the placenta, which is a disc-shaped organ that attaches to the fetus via a/an .
Problem 9
Match the structures of the embryo with the primary germ layer from which each developed. Each germ layer will have more than one structure.
________Endoderm
________Mesoderm
________Ectoderm
a. Nervous system
b. Linings of the digestive tract
c. Skeletal structures
d. Epidermis of the skin
e. Thyroid and parathyroid glands
f. Skeletal muscles
Problem 10
What are the two types of embryonic folding?
Problem 11
Match the fetal developments to the correct month of gestation.
Month 3
Month 4
Month 5
Month 6
Month 7
Months 8 and 9
a. A downy hair called lanugo develops.
b. Organs specialize and grow.
c. Lungs begin to produce surfactant.
d. The heartbeat can be heard with a stethoscope.
e. Fetus turns to the vertex position.
f. Ossification begins in most bones.
Problem 12
Match the structures found in the fetal circulation with what each fetal structure becomes after birth:
Foramen ovale
Ductus arteriosus
Ductus venosus
a. Ligamentum venosum
b. Fossa ovalis
c. Ligamentum arteriosum
Problem 13
The ________ is responsible for secreting the hormone human chorionic gonadotropin (hCG).
a. Syncytiotrophoblast
b. Ovary
c. Endometrium
d. Morula
Problem 14
Which of the following hormones secreted during pregnancy assists with increasing the mother's blood volume?
a. Estrogen
b. Progesterone
c. Cortisol
d. Aldosterone
e. Parathyroid hormone
Problem 15
Number the sequence of events that are responsible for initiating labor.
Hypothalamus of the mother and fetus stimulate the placenta to secrete prostaglandins.
Fetal cortisol levels increase and stimulate the placenta to release estrogen.
Prostaglandins and oxytocin stimulate the uterus to contract.
Estrogen stimulates the myometrium to form oxytocin receptors.
Problem 16a
Mark the following statements about the stages of labor as true or false. If a statement is false, correct it to make a true statement.
The dilation stage is the time from the onset of labor until the cervix is fully expanded.
Problem 16b
Mark the following statements about the stages of labor as true or false. If a statement is false, correct it to make a true statement.
The placental stage is the time after delivery of the infant when the placenta and the attached fetal extraembryonic membranes are delivered.
Problem 16c
Mark the following statements about the stages of labor as true or false. If a statement is false, correct it to make a true statement.
The expulsion stage of labor is usually longer than the dilation or placental stages.