Correct Answer: B

Rationale: A major limitation of systematic observation is that it tells investigators little about the reasoning behind responses and behaviors. Systematic observation focuses more on recording observable behaviors rather than delving into the underlying reasons or thought processes driving those behaviors. Choices A, C, and D are incorrect because systematic observation can indeed provide detailed information on how participants actually behave, it doesn't necessarily underestimate the capacities of individuals who struggle with verbal expression, and it doesn't solely ignore participants with poor memories as it can capture behavior in real-time regardless of memory recall.

Correct Answer: B

Rationale: The correct answer is B. During prenatal development, the ectoderm folds over to form the neural tube, which eventually develops into the brain and spinal cord. The neural tube is the precursor to the central nervous system, including the primitive spinal cord. Choices A, C, and D are incorrect because the mesoderm does not form the neural tube, the endoderm is not involved in the formation of the central nervous system, and neuron tract is not the structure that forms the primitive spinal cord.

Correct Answer: C

Rationale: Dr. Singh's beliefs align with Erik Erikson's psychosocial theory of development. Erikson proposed that individuals go through a series of psychosocial stages, with each stage characterized by a basic conflict that must be resolved to achieve healthy development. This conflict is resolved along a continuum from positive to negative outcomes. Choice A, G. Stanley Hall, is incorrect as his work focused on adolescence and evolutionary psychology. Choice B, Sigmund Freud, is incorrect as his psychoanalytic theory is more focused on the unconscious mind and psychosexual stages. Choice D, B. F. Skinner, is incorrect as he is associated with behaviorism and operant conditioning, which is different from Erikson's psychosocial theory.

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.

Correct Answer: A

Rationale: Vygotsky's emphasis on culture and social experience did not lead him to neglect the biological side of development. Instead, he believed that biological factors and social influences interact to shape cognitive development. Choice A is correct because it reflects Vygotsky's view that biological factors and social experiences work together in cognitive development. Choices B, C, and D are incorrect as Vygotsky's emphasis was not on overemphasizing heredity, focusing solely on independent efforts of children, or placing too much emphasis on children's capacity to shape their own development.