Correct Answer: D

Rationale: The correct answer is D, Zygote. A zygote is formed when the 23 chromosomes from the ovum and sperm combine during conception. It is the initial cell formed and marks the beginning of a new organism. Choice A, Embryo, is incorrect as an embryo is formed later in the development process. Choice B, DNA, is incorrect as DNA is the genetic material within the chromosomes but is not the name of the new cell formed after fertilization. Choice C, Fetus, is incorrect as a fetus is the stage of prenatal development that occurs well after the zygote stage.

Correct Answer: C

Rationale: The correct answer is C: Secondary circular reactions. Secondary circular reactions are repeated actions that infants engage in to trigger a response from the environment, such as the baby cooing to make the mom smile. This behavior is characterized by a focus on the external environment and the repetition of actions to achieve a desired response. Choices A, B, and D are incorrect. Reflexes (choice A) are automatic, involuntary responses to a stimulus, while primary circular reactions (choice B) involve the repetition of actions primarily for the infant's own enjoyment rather than to elicit a response from the environment. Tertiary circular reactions (choice D) refer to the experimentation with new behaviors and variations in the way the infant interacts with the environment.

Correct Answer: C

Rationale: According to the diathesis-stress model, having a predisposition towards mental illness increases the risk but does not guarantee the development of a mental disorder. Choice A is incorrect as the model does not imply certainty. Choice B is incorrect as having a predisposition does affect the chances. Choice D is incorrect as the model does have an impact on the likelihood of developing a mental disorder.

Correct Answer: A

Rationale: Pruning is the process of eliminating unused synapses in the brain. This process helps the brain to become more efficient by strengthening important connections and eliminating unnecessary ones. Choice B is incorrect because pruning is about eliminating synapses, not developing them. Choice C is incorrect as it refers to the general concept of connections between neurons, not specifically about pruning. Choice D is incorrect as it describes the myelin sheath, which is responsible for rapid transmission of information along neurons, not pruning.

Correct Answer: B

Rationale: A negative relationship means that as one variable increases, the other decreases, so higher perceived parental perfectionism is associated with lower life satisfaction.