Correct Answer: D

Rationale: The correct order of the three stages of prenatal development is germinal stage, embryonic stage, and fetal stage. During the germinal stage, the fertilized egg rapidly divides and implants in the uterine wall. The embryonic stage follows, where major organs and systems begin to develop. Finally, during the fetal stage, the developing organism is known as a fetus and continues to grow and mature. Choice A is incorrect because it has the stages in the wrong order. Choice B is incorrect as it also presents the stages out of order. Choice C is incorrect as it reverses the order of the stages. Therefore, the correct answer is D.

Correct Answer: D

Rationale: John Watson was a key figure in the development of behaviorism, which advocated for focusing on observable behavior rather than the study of consciousness. Choice D is the correct answer because Watson believed that psychology should abandon the study of consciousness. Choices A, B, and C are incorrect because Watson's approach emphasized behavior and rejected the importance of consciousness, introspection, or confining psychology to only mentally ill individuals.

Correct Answer: B

Rationale: The correct answer is B, Monozygotic twin. A monozygotic twin, also known as an identical twin, is the result when a single zygote splits into two parts, leading to the development of two genetically identical individuals. Choices A, C, and D are incorrect because they do not accurately describe the scenario where a single zygote splits into two parts to form identical twins. Dizygotic twin (Choice A) refers to fraternal twins, which result from two separate eggs fertilized by two different sperm cells. Fraternal twin (Choice C) is another term for dizygotic twins, arising from two separate zygotes. Nonidentical twin (Choice D) is a synonymous term for dizygotic or fraternal twins, indicating that they are not genetically identical.

Correct Answer: B

Rationale: Wilhelm Wundt's approach emphasized the study of conscious experience, marking a shift towards scientific methods in psychology. Choice A, observable behavior, is associated with behaviorism and not Wundt's structuralism. Choice C, unconscious motivation, is more aligned with Freud's psychoanalytic theory. Choice D, the functions of behavior, relates more to functionalism, which was developed by William James.

Correct Answer: D

Rationale: The correct answer is Dopamine. Dopamine was initially thought to be the primary cause of schizophrenia. This neurotransmitter hypothesis was based on the observation that drugs that increase dopamine activity can worsen symptoms of schizophrenia, while drugs that decrease dopamine activity can improve symptoms. Choices A, B, and C are incorrect because GABA, serotonin, and epinephrine were not the neurotransmitters initially believed to be the cause of schizophrenia.