HESI Focus on Maternity Exam

Correct Answer: C

Rationale: Dizygotic (DZ) twins share approximately 50% of their genes. This is because dizygotic twins, also known as fraternal twins, originate from two separate fertilized eggs and share similar genetic similarity to regular siblings. Choice A (100%) is incorrect because if twins shared 100% of their genes, they would be identical twins (monozygotic). Choice B (75%) is incorrect as it is not the typical genetic similarity seen in dizygotic twins. Choice D (25%) is incorrect as it represents a significantly lower genetic similarity than what is observed in dizygotic twins.

Correct Answer: D

Rationale: The correct answer is Monozygotic (MZ) twins. Monozygotic twins, also known as identical twins, share 100% of their genes because they originate from the same fertilized egg that splits into two. Fraternal twins (choice B), also known as dizygotic (DZ) twins (choice C), result from two separate fertilized eggs and share approximately 50% of their genes. Biovular twins (choice A) is not a term used in genetics and does not describe a type of twinning.

Correct Answer: B

Rationale: The correct nursing action is to gradually warm the infant under a radiant heat source. The infant is presenting with signs of cold stress, indicated by cyanotic extremities and a low body temperature. Gradual warming is crucial to stabilize the infant's temperature and prevent further complications. Administering oxygen, notifying the pediatrician, or performing a heel-stick are not the priority actions in this scenario and may not address the immediate need to raise the infant's body temperature.

Correct Answer: D

Rationale: The most critical information for the nurse to provide the client is ensuring that there is no significant vaginal bleeding before discharge. This is vital to prevent complications such as postpartum hemorrhage. Options A, B, and C are important aspects of postpartum care, but assessing and managing vaginal bleeding takes precedence due to its potential seriousness.

Correct Answer: A

Rationale: A zygote is the correct answer. It is the initial cell formed when a sperm cell fertilizes an egg cell, marking the beginning of human development. Choice B, gonadotrope, is incorrect as it refers to a type of hormone-secreting cell in the pituitary gland. Choice C, embryo, is incorrect as it is the stage of development after the zygote has implanted into the uterine wall and undergone initial cell divisions. Choice D, chromaffin, is incorrect as it refers to cells found in the adrenal medulla that produce and store catecholamines.