Correct Answer: D

Rationale: The correct answer is D. A sperm cell is indeed one of the smallest cells in the human body, much smaller than an egg cell. Choice A is incorrect as sperm cells are much smaller than egg cells. Choice B is incorrect because a sperm cell carries either an X or a Y chromosome, not two Y chromosomes. Choice C is incorrect since sperm cells move in a purposeful manner guided by various factors within a woman's reproductive tract, not randomly.

Correct Answer: B

Rationale: Class II cardiac disease is symptomatic with ordinary activity. Women in this category need to avoid heavy exertion and limit regular activities as symptoms dictate. Stress is greatest between weeks 28 and 32 of gestation, when hemodynamic changes reach their maximum. Class III cardiac disease is symptomatic with less-than-ordinary activity. These women need bed rest most of the day and face the possibility of hospitalization near term. Class I cardiac disease is asymptomatic at normal levels of activity. These women can perform limited normal activities with discretion, although they still need a good amount of sleep.

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: 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.

Correct Answer: D

Rationale: The correct answer is D. A sperm cell is indeed one of the smallest cells in the human body, much smaller than an egg cell. Choice A is incorrect as sperm cells are much smaller than egg cells. Choice B is incorrect because a sperm cell carries either an X or a Y chromosome, not two Y chromosomes. Choice C is incorrect since sperm cells move in a purposeful manner guided by various factors within a woman's reproductive tract, not randomly.