HESI Focus on Maternity Exam

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: A

Rationale: Calculation: (6 mg/dose) / (10 mg/mL) = 0.6 mL per dose. The correct answer is 0.6 mL. This calculation is obtained by dividing the dose needed (6 mg) by the concentration available (10 mg/mL). The resulting value is 0.6 mL per dose. Choices B, C, and D are not applicable as the correct answer has been calculated accurately.

Correct Answer: A

Rationale: The correct answer is A: 'A Rh-negative mother who has an Rh-positive infant.' In cases where the newborn is born post-term, the mismatched Rh factor between the mother (Rh-negative) and the infant (Rh-positive) can lead to hemolytic disease of the newborn. This condition occurs when maternal antibodies attack fetal red blood cells, causing hemolysis. This can result in jaundice, anemia, and other serious complications for the infant. Choices B, C, and D are incorrect because they do not reflect the mismatched Rh factor scenario that poses a risk for hemolytic disease of the newborn.

Correct Answer: C

Rationale: During phototherapy using a lamp, it is crucial to protect the newborn's eyes from the light to prevent damage. Closing the newborn's eyes beneath the shield is essential for this purpose. Applying lotion to the skin (Choice A) is not recommended as it can intensify the effects of the phototherapy. Giving glucose water (Choice B) is unrelated to the phototherapy process and is not indicated. Dressing the newborn in clothing (Choice D) may hinder the effectiveness of the phototherapy by blocking the light exposure to the skin.

Correct Answer: A

Rationale: The correct answer is 'allele.' An allele refers to one of two or more versions of a gene located at the same position on a chromosome. In genetics, alleles are responsible for variations in inherited traits. Choice B, 'zygote,' is incorrect as a zygote is a fertilized egg cell formed by the fusion of two gametes. Choice C, 'autosome,' is incorrect as autosomes are non-sex chromosomes that determine an individual's genetic traits excluding sex-linked characteristics. Choice D, 'node,' is incorrect as it does not relate to the concept of genes or genetic inheritance.