HESI Focus on Maternity Exam

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.

Correct Answer: A

Rationale: Nagele's Rule is a common method used to estimate the due date. To calculate it, subtract 3 months and add 7 days to the first day of the last menstrual period. In this case, if the last menstrual period started on July 10, subtracting 3 months (April) and adding 7 days gives an estimated due date of April 17. This is the correct answer. Choices B, C, and D are incorrect because they do not follow the Nagele's Rule calculation method.

Correct Answer: C

Rationale: Progestin is the synthetic hormone used to prevent miscarriages. While it is beneficial in maintaining pregnancy, in some cases, it can lead to masculinization of the fetus. Testosterone (Choice A) and estrogen (Choice B) are not typically used to prevent miscarriages and do not cause masculinization of the fetus in this context. Oxytocin (Choice D) is a hormone involved in labor and breastfeeding, but it is not used to prevent miscarriages nor does it cause masculinization of the fetus.

Correct Answer: A

Rationale: The correct answer is A. Positioning the car seat at a 45-degree angle is crucial to prevent the baby's head from falling forward, which can obstruct the airway. Choice B is incorrect because the recommendation is to keep the car seat rear-facing until the baby reaches the height or weight limit set by the car seat manufacturer, typically beyond 12 months. Choice C is incorrect as the harness should be snugly placed at or below the baby's shoulders, not above. Choice D is incorrect as the retainer clip should be positioned at armpit level to secure the harness straps properly.

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.