Although the male ejaculate contains hundreds of millions of sperm, ________. a. most do

View this time-lapse movie (http://openstaxcollege.org/l/conceptus) of a conceptus starting at day 3. What is the first structure you see? At what point in the movie does the blastocoel first appear? What event occurs at the end of the movie?

Use this interactive tool (http://openstaxcollege.org/ l/embryogenesis) to view the process of embryogenesis from the perspective of the conceptus (left panel), as well as fetal development viewed from a maternal cross-section (right panel). Can you identify when neurulation occurs in the embryo?

Visit this site (http://openstaxcollege.org/l/pregstages) for a summary of the stages of pregnancy, as experienced by the mother, and view the stages of development of the fetus throughout gestation. At what point in fetal development can a regular heartbeat be detected?

Sperm and ova are similar in terms of ________. a. size b. quantity produced per year c. chromosome number d. flagellar motility

Although the male ejaculate contains hundreds of millions of sperm, ________. a. most do not reach the oocyte b. most are destroyed by the alkaline environment of the uterus c. it takes millions to penetrate the outer layers of the oocyte d. most are destroyed by capacitation

As sperm first reach the oocyte, they will contact the ________. a. acrosome b. corona radiata c. sperm-binding receptors d. zona pellucida

Fusion of pronuclei occurs during ________. a. spermatogenesis b. ovulation c. fertilization d. capacitation

Sperm must first complete ________ to enable the fertilization of an oocyte. a. capacitation b. the acrosomal reaction c. the cortical reaction d. the fast block

Cleavage produces daughter cells called ________. a. trophoblasts b. blastocysts c. morulae d. blastomeres

The conceptus, upon reaching the uterus, first ________. a. implants b. divides c. disintegrates d. hatches

The inner cell mass of the blastocyst is destined to become the ________. a. embryo b. trophoblast c. chorionic villi d. placenta

Which primary germ layer gave rise to the cells that eventually became the central nervous system? a. endoderm b. ectoderm c. acrosome d. mesoderm

What would happen if the trophoblast did not secrete hCG upon implantation of the blastocyst? a. The cells would not continue to divide. b. The corpus luteum would continue to produce progesterone and estrogen. c. Menses would flush the blastocyst out of the uterus. d. The uterine mucosa would not envelop the blastocyst.

During what process does the amnion envelop the embryo? a. embryonic folding b. gastrulation c. implantation d. organogenesis

The placenta is formed from ________. a. the embryos mesenchymal cells b. the mothers endometrium only c. the mothers endometrium and the embryos chorionic membrane d. the mothers endometrium and the embryos umbilical cord

The foramen ovale causes the fetal circulatory system to bypass the ________. a. liver b. lungs c. kidneys d. gonads

What happens to the urine excreted by the fetus when the kidneys begin to function? a. The umbilical cord carries it to the placenta for removal. b. The endometrium absorbs it. c. It adds to the amniotic fluid. d. It is turned into meconium.

During weeks 912 of fetal development, ________. a. bone marrow begins to assume erythrocyte production b. meconium begins to accumulate in the intestines c. surfactant production begins in the fetal lungs d. the spinal cord begins to be myelinated

Progesterone secreted by the placenta suppresses ________ to prevent maturation of ovarian follicles. a. LH and estrogen b. hCG and FSH c. FSH and LH d. estrogen and hCG

Which of the following is a possible culprit of morning sickness? a. increased minute respiration b. decreased intestinal peristalsis c. decreased aldosterone secretion d. increased blood volume

How does the decrease in progesterone at the last weeks of pregnancy help to bring on labor? a. stimulating FSH production b. decreasing the levels of estrogens c. dilating the cervix d. decreasing the inhibition of uterine contractility

Which of these fetal presentations is the easiest for vaginal birth? a. complete breech b. vertex occiput anterior c. frank breech d. vertex occiput posterior

Which of these shunts exists between the right and left atria? a. foramen ovale b. ductus venosus c. ductus arteriosis d. foramen venosus

Why is brown fat important? a. It is the newborns primary source of insulation. b. It can be broken down to generate heat for thermoregulation. c. It can be broken down for energy between feedings. d. It can be converted to white fat.

Constriction of umbilical blood vessels during vaginal birth ________. a. causes respiratory alkalosis b. inhibits the respiratory center in the brain c. elevates carbon dioxide levels in the blood d. both a and b

Alveoli are connected to the lactiferous sinuses by ________. a. lactocytes b. lactiferous ducts c. nipple pores d. lobules

How is colostrum most important to a newborn? a. It helps boost the newborns immune system. b. It provides much needed fat. c. It satisfies the newborns thirst. d. It satisfies the infants appetite.

Mature breast milk ________. a. has more sodium than cows milk b. has more calcium than cows milk c. has more protein than cows milk d. has more fat than cows milk

Marfan syndrome is inherited in an autosomal dominant pattern. Which of the following is true? a. Female offspring are more likely to be carriers of the disease. b. Male offspring are more likely to inherit the disease. c. Male and female offspring have the same likelihood of inheriting the disease. d. Female offspring are more likely to inherit the disease.

In addition to codominance, the ABO blood group antigens are also an example of ________. a. incomplete dominance b. X-linked recessive inheritance c. multiple alleles d. recessive lethal inheritance

Zoe has cystic fibrosis. Which of the following is the most likely explanation? a. Zoe probably inherited one faulty allele from her father, who is a carrier, and one normal allele from her mother. b. Zoe probably inherited one faulty allele from her mother, who must also have cystic fibrosis, and one normal allele from her father. c. Zoe must have inherited faulty alleles from both parents, both of whom must also have cystic fibrosis. d. Zoe must have inherited faulty alleles from both parents, both of whom are carriers.

Darcy and Raul are having difficulty conceiving a child. Darcy ovulates every 28 days, and Rauls sperm count is normal. If we could observe Rauls sperm about an hour after ejaculation, however, wed see that they appear to be moving only sluggishly. When Rauls sperm eventually encounter Darcys oocyte, they appear to be incapable of generating an adequate acrosomal reaction. Which process has probably gone wrong?

Sherrise is a sexually active college student. On Saturday night, she has unprotected sex with her boyfriend. On Tuesday morning, she experiences the twinge of midcycle pain that she typically feels when she is ovulating. This makes Sherrise extremely anxious that she might soon learn she is pregnant. Is Sherrises concern valid? Why or why not?

Approximately 3 weeks after her last menstrual period, a sexually active woman experiences a brief episode of abdominopelvic cramping and minor bleeding. What might be the explanation?

The Food and Nutrition Board of the Institute of Medicine recommends that all women who might become pregnant consume at least 400 g/day of folate from supplements or fortified foods. Why?

What is the physiological benefit of incorporating shunts into the fetal circulatory system?

Why would a premature infant require supplemental oxygen?

Devin is 35 weeks pregnant with her first child when she arrives at the birthing unit reporting that she believes she is in labor. She states that she has been experiencing diffuse, mild contractions for the past few hours. Examination reveals, however, that the plug of mucus blocking her cervix is intact and her cervix has not yet begun to dilate. She is advised to return home. Why?

Janine is 41 weeks pregnant with her first child when she arrives at the birthing unit reporting that she believes she has been in labor for days but that its just not going anywhere. During the clinical exam, she experiences a few mild contractions, each lasting about 1520 seconds; however, her cervix is found to be only 2 cm dilated, and the amniotic sac is intact. Janine is admitted to the birthing unit and an IV infusion of pitocin is started. Why?

Describe how the newborns first breath alters the circulatory pattern.

Newborns are at much higher risk for dehydration than adults. Why?

Describe the transit of breast milk from lactocytes to nipple pores.

A woman who stopped breastfeeding suddenly is experiencing breast engorgement and leakage, just like she did in the first few weeks of breastfeeding. Why?

Explain why it was essential that Mendel perform his crosses using a large sample size?

How can a female carrier of an X-linked recessive disorder have a daughter who is affected?