A 20-week-old fetus can __________.

Correct Answer: A

Rationale: A 20-week-old fetus is able to be stimulated as well as irritated by sounds because by this stage of prenatal development, the fetus's auditory system is already well-developed. It can respond to external sounds and may even startle or move in reaction to loud noises.

Correct Answer: C

Rationale: One strength of the cross-sectional design is that it is not plagued with dropout or practice effects. This is because cross-sectional studies assess different individuals at the same point in time, eliminating the risk of participants dropping out or improving due to repeated measures.

Correct Answer: D

Rationale: High doses of caffeine contained in coffee and tea have been linked to an increased risk of low birth weight. Consuming large amounts of caffeine during pregnancy can interfere with the baby's growth and development, leading to a lower birth weight than expected. It is important for pregnant women to limit their caffeine intake to reduce the risk of complications such as low birth weight.

Correct Answer: A

Rationale: In an experimental study, the independent variable is the factor being manipulated or controlled by the researcher. In this case, the frequency of read-alouds is the variable that researchers would intentionally change or vary to see its effect on the dependent variable, which is the children's vocabulary scores. The other options (B. type of books parents read, C. child's vocabulary score, and D. difficulty of vocabulary words) are not the independent variable in this study as they are either irrelevant or are the outcome being measured.

Correct Answer: A

Rationale: The correlation of +.49 indicates a moderate strength of relationship between illegal drug use and levels of adolescent delinquency. The positive correlation indicates that as one variable (illegal drug use) increases, the other variable (adolescent delinquency) also tends to increase.

Correct Answer: B

Rationale: Lillian, who uses flowcharts to map precise steps individuals use to solve problems and complete tasks, is likely an information-processing theorist. Information-processing theorists focus on how people take in, store, and retrieve information to solve problems and make decisions, which aligns with Lillian's use of flowcharts to map out problem-solving steps.

Correct Answer: B

Rationale: The two main types of designs used in all research on human behavior are correlational and experimental. Correlational research examines the relationship between two or more variables without establishing causation, while experimental research involves manipulating one variable to observe the effect on another variable. These two types of designs are fundamental in understanding and studying human behavior.

Correct Answer: A

Rationale: The embryonic disk becomes the new organism. It is a cluster of cells within the blastocyst that will develop into the fetus during the early stages of prenatal development. This cluster of cells is responsible for giving rise to all the tissues and organs of the developing organism.

Correct Answer: D

Rationale: Cigarette smoking by a caregiver doubles the risk of SIDS. Secondhand smoke exposure can increase the likelihood of SIDS due to the toxins and chemicals present in cigarette smoke. It is important to have a smoke-free environment for infants to reduce the risk of SIDS.