Question 1

Describe how a zygote develops into a full-term fetus, noting the characteristics of the three stages of prenatal development.

Accepted Answer

The answer should include the following information: The three stages of prenatal development are the germinal period, the embryonic period, and the fetal period. The germinal period is the first two weeks of prenatal development. During this period, the single-celled fertilized egg (the "zygote") undergoes rapid cell division and implants in the wall of the mother's uterus. By the end of the germinal period, the zygote has become a cluster of cells called the embryo. The embryonic period extends through week 8 and is a time of rapid growth, intensive cell differentiation and formation of the major organs and systems of the body. At this stage the embryo is contained in the fluid-filled amniotic sac and depends on the umbilical cord for nourishment, oxygen, and water as well as the removal of carbon dioxide and wastes. The placenta acts as a filter to prevent many harmful substances in the mother's blood from reaching the embryo. By the end of the embryonic period, the embryo has grown from the size of the head of a pin to over an inch in length, weighing about an ounce. Although its head accounts for about half of its body size, the embryo now looks distinctly human. The fetal period extends from the beginning of the third month onward. During this stage, the body systems grow and reach maturity in preparation for birth. By the end of the third month the fetus can move its arms, legs, mouth, and head and is capable of reflexive responses. During the fourth month the mother can feel the fetus moving (termed "quickening"), and the fetus begins to have distinct sleep-wake cycles and periods of activity. During the sixth month the fetus' brain becomes similar to that of a newborn baby. During the final two months, the fetus will double in weight and gain three to four pounds of body fat, which will help with temperature regulation after birth.

Question 2

Define teratogens, and list five known teratogens.

Accepted Answer

The answer should include the following information: Because there are more than five known teratogens, students can include any five listed in the second part of the answer. Teratogens are harmful agents or substances that can cause malformations or defects in an embryo or fetus. Known teratogens include: exposure to radiation; toxic chemicals and metals, such as mercury, PCBs, and lead; viruses and bacteria, such as German measles, syphilis, genital herpes, and HIV; prescription painkillers and other prescription and nonprescription drugs; addictive drugs, including heroin, sedatives, cocaine, amphetamines, and methamphetamine; maternal smoking and exposure to secondhand smoke; and alcohol.

Question 3

Describe Renée Baillargeon's research, and explain how it challenged some of Piaget's conclusions.

Accepted Answer

The answer should include the following information: Renée Baillargeon's research focused on the notion that both infants and adults will look longer at "surprising" events that appear to contradict their understanding of the world. Baillargeon used a paradigm in which an infant first watched an expected event and then was shown an unexpected event. If the unexpected event violated the infant's understanding of the world (that is, surprised the infant) then the infant would look longer at the unexpected event versus the expected event. Using this paradigm, Baillargeon and her colleagues found that infants as young as Answer: 5 months of age display object permanence. In Baillargeon's research, object permanence was attained much earlier than in Piaget's research. It is important to note that the task used by Piaget to measure object permanence required a certain level of motor control on the part of the child. Piaget would hide an object under a cloth and then record whether or not the child reached for the object. If the child reached under the cloth for the object, then Piaget would interpret this action as a sign of object permanence. If the child did not reach under the cloth, then Piaget assumed that the object simply did not exist for the child (that is, the child lacked object permanence). By using tasks based on visual functions rather than motor control, Baillargeon found that Piaget may have significantly underestimated the cognitive abilities of infants and young children.

Question 4

How does the child who is in the concrete operational stage of development differ from the child who is in the formal operational stage of cognitive development?

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Question 5

Define genotype and phenotype and give an example of how the interaction of genetics and environment can influence phenotype.

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Question 6

Define epigenetics and describe the different ways that gene expression can be triggered.

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Question 7

Describe research on the effect of educational baby videos on language development, and indicate whether the research supports the claim that baby videos work to accelerate language and cognitive development.

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Question 8

In regards to physical development in infancy and childhood, describe the cephalocaudal and proximodistal trends. How do these trends in infant development compare to the developmental sequence for body segments in the womb?

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Question 9

Identify the sensory capabilities and reflexes of newborns and describe how these abilities enhance their chances for survival.

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Question 10

Compare the typical sleeping arrangements of families with infants in the United States with those of other cultures, and discuss how these differences reflect different cultural beliefs and norms.

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Question 11

Identify the major stages of the lifespan.

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Question 12

How did researchers Alexander Thomas and Stella Chess classify the temperamental patterns of infants? Describe characteristics of each temperamental pattern.

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Question 13

Define the terms "zygote," "chromosomes," "genes," and "DNA," and describe how they are related.

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Question 14

List and describe the major milestones in infant motor development, and specify the typical age range for acquiring a particular motor skill during infancy. Are simple statistical averages a meaningful predictor of when infants will acquire a particular skill?

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Question 15

Describe the role of stem cells and the neural tube in the development of three main regions of the brain.

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Question 16

Describe the typical progression of language production up to age 3 in babies with normal hearing.

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Question 17

Carl and Andy are both toddlers. Carl is securely attached and Andy is insecurely attached. They are enrolled in a research study in which they will be exposed to the Strange Situation. What is the Strange Situation and how would you expect Carl and Andy to differ in terms of their reactions?

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Question 18

What cognitive abilities and limitations characterize a child's thinking during the sensorimotor and preoperational stages?

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Question 19

Describe the function of alleles, specify what the best-known pattern of allele variation is, and give an example to illustrate the concept of dominant and recessive genes.

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Question 20

Describe Jean Piaget's views about the nature of cognitive development in children.

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Quiz 9: Section 1: Lifespan Development