Nokea
Which statement about a blastocyst is true?
- A. It consists of a single cell.
- B. It is a structure that feeds the developing organism.
- C. Between the seventh and ninth days, it burrows deep into the uterine lining.
- D. It is a membrane that helps to keep the temperature of the prenatal world constant.
Correct Answer: C
Rationale: The statement that is true about a blastocyst is that between the seventh and ninth days, it burrows deep into the uterine lining. This process, known as implantation, is essential for the blastocyst to establish a connection with the mother's body and receive nutrients for further development. It is a critical stage in prenatal development and sets the foundation for pregnancy. Choices A, B, and D are incorrect. A blastocyst is not a single cell but rather a structure composed of many cells. It is not a structure that feeds the developing organism; instead, it implants in the uterine lining to receive nutrients. It is not a membrane that regulates temperature but plays a crucial role in the initial stages of pregnancy by implanting in the uterus.
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Longitudinal research can identify common patterns as well as individual differences in development because the investigator __________.
- A. studies groups of participants differing in age at the same point in time
- B. randomly assigns participants to treatment conditions
- C. tracks the performance of each person over time
- D. conducts quasi-experiments, comparing conditions that already exist
Correct Answer: C
Rationale: Longitudinal research involves tracking the performance of each person over time. By doing so, researchers can observe common patterns in development among a group of individuals and also identify individual differences in how each person progresses over time. This methodology allows researchers to gather data on the same individuals repeatedly, offering insights into how development unfolds over the lifespan. Choices A, B, and D are incorrect because longitudinal research focuses on observing individuals over time rather than studying groups at a single point, randomly assigning participants to treatments, or conducting quasi-experiments.
During the second trimester, a white, cheeselike substance called __________ emerges on the skin.
- A. lanugo
- B. corpus luteum
- C. vernix
- D. chorion
Correct Answer: C
Rationale: During the second trimester of pregnancy, a white, cheeselike substance called vernix emerges on the skin of the developing fetus. Vernix is a protective layer that helps prevent the skin from becoming waterlogged during the time in the amniotic fluid. Choice A, lanugo, is incorrect as lanugo refers to the fine, soft hair that covers the body of a fetus. Choice B, corpus luteum, is incorrect as it is a temporary endocrine structure involved in the menstrual cycle. Choice D, chorion, is incorrect as it is one of the membranes that surround the embryo and later the fetus.
It is difficult to isolate the precise damage caused by illegal drugs during pregnancy because __________.
- A. most drug-using mothers refuse to participate in teratology research
- B. the majority of babies born to drug-using mothers do not survive for more than a few days
- C. most drug-using mothers quit using illegal drugs during the first trimester of pregnancy
- D. drug users often take several drugs, display other high-risk behaviors, and suffer from other stresses
Correct Answer: D
Rationale: The difficulty in isolating the precise damage caused by illegal drugs during pregnancy is due to the fact that drug users often take several drugs, display other high-risk behaviors, and suffer from other stresses. This makes it challenging to identify the specific impact of each individual factor on prenatal development. Choices A, B, and C are incorrect because they do not address the complexity of the situation involving drug users during pregnancy. Most drug-using mothers refusing to participate in teratology research, the majority of babies not surviving, or drug-using mothers quitting during the first trimester do not directly explain the difficulty in isolating the precise damage caused by illegal drugs during pregnancy.
What is the most common approach to controlling pain during labor?
- A. an anesthetic
- B. a spinal block
- C. fetal monitoring
- D. epidural analgesia
Correct Answer: D
Rationale: Epidural analgesia is the most common approach to controlling pain during labor. It involves the administration of pain medication through a catheter placed in the epidural space of the spine, providing pain relief while allowing the mother to remain alert and participate in the birthing process. It is preferred by many women due to its effectiveness in reducing labor pain. Choices A, B, and C are incorrect as they do not directly address pain management during labor. While an anesthetic and a spinal block are forms of pain relief, epidural analgesia is specifically the most common method used for pain control during labor.
Liz is 36 weeks pregnant. A rise in her baby's heart rate is probably followed within five seconds by __________.
- A. a burst of motor activity
- B. a period of sleep
- C. a rise in Liz's heart rate
- D. a drop in Liz's body temperature
Correct Answer: A
Rationale: A rise in the baby's heart rate during pregnancy is usually followed within five seconds by a burst of motor activity. This indicates that the baby is responding to stimuli and is an important sign of healthy fetal development. A period of sleep, a rise in Liz's heart rate, or a drop in Liz's body temperature are not typically immediate responses to changes in the baby's heart rate. Sleep is less likely to be a direct response to changes in heart rate, Liz's heart rate is independent of the baby's heart rate changes, and a drop in Liz's body temperature is not a common immediate response to fetal heart rate changes.