Correct Answer: B

Rationale: The synapse is the correct answer. It is the site where communication between neurons occurs through the release and reception of neurotransmitters. Choice A, neuron, is incorrect as it is the cell itself rather than a specific site of communication. Choice C, axon, is also incorrect as it is a part of the neuron that transmits signals away from the cell body. Choice D, dendrite, is not the correct answer either, as dendrites receive signals from other neurons but do not release neurotransmitters for communication.

Correct Answer: B

Rationale: According to Freud's theory of psychosexual development, if a person does not resolve a particular stage successfully, they become fixated at that stage. This fixation can lead to behavior patterns characteristic of that stage in later life. In this context, 'defended' is incorrect because it does not align with Freud's theory of fixation. 'Repressed' is not the correct choice as it refers to the unconscious suppression of thoughts or desires. 'Displaced' involves redirecting emotions from their original source to a substitute target, which is not the concept Freud associated with unresolved psychosexual stages.

Correct Answer: D

Rationale: Down syndrome is caused by possessing an extra chromosome in chromosome 21, not a chemical imbalance (choice A), a gene on the X chromosome (choice B), or possessing an extra X chromosome (choice C). The presence of an extra copy of chromosome 21, also known as trisomy 21, leads to the characteristic features and health problems associated with Down syndrome.

Correct Answer: C

Rationale: The interpersonal perspective emphasizes social rather than inner determinants of behavior. Choice A is incorrect as the interpersonal perspective focuses on social interactions rather than being a reaction against psychoanalysis. Choice B is incorrect as the interpersonal perspective is not specifically attributed to Erik Erikson. Choice D is incorrect as the most influential humanistic perspective today would be humanistic psychology, not the interpersonal perspective.

Correct Answer: B

Rationale: The correct answer is B: 'less cortical gray matter than those raised by their parents.' Studies have shown that children raised in orphanages tend to have less cortical gray matter compared to those raised by their parents. This is due to the lack of individualized care, attention, and stimulation that can negatively impact brain development. Choices A, C, and D are incorrect because there is no direct correlation between cortical gray matter and the number of friendships when comparing children raised in orphanages and those raised by their parents.