Maternity HESI Practice Questions

Correct Answer: C

Rationale: Cystic fibrosis is a genetic disorder caused by inheriting two copies of a recessive gene, one from each parent. This means that both parents must carry at least one copy of the faulty gene for a child to inherit the condition. Choice A is incorrect because cystic fibrosis is not linked to the sex chromosomes. Choice B is incorrect as cystic fibrosis is not caused by an abnormality in the 21st pair of chromosomes but by a specific gene mutation. Choice D is also incorrect as cystic fibrosis is not related to the Y chromosome, which is specific to males.

Correct Answer: B

Rationale: The correct answer is B: double helix. DNA is structured as a double helix, resembling a twisted ladder made up of two strands of nucleotides. Choice A, single spiral, is incorrect as DNA is not a single spiral structure. Choice C, sphere, is incorrect as DNA does not form a spherical shape. Choice D, cube, is incorrect as DNA does not have a cubic structure. Understanding the double helix structure of DNA is essential as it allows for the storage and transmission of genetic information in living organisms.

Correct Answer: B

Rationale: Mitosis is the correct answer because it is the process of cell division in which a cell duplicates its DNA and divides into two identical daughter cells. During mitosis, the DNA is replicated, and each daughter cell receives an identical copy of the genetic material. Amniocentesis is a medical procedure to collect amniotic fluid for prenatal genetic testing and is not related to DNA duplication. Meiosis is a type of cell division that produces gametes with half the genetic material of the parent cell, leading to genetic diversity. Mutation is a permanent alteration in the DNA sequence that can lead to genetic variations but is not the process of DNA duplication.

Correct Answer: C

Rationale: Sickle-cell anemia is a genetic disorder caused by inheriting two copies of a recessive gene, one from each parent. The correct answer is C. Choice A is incorrect because sickle-cell anemia is not primarily caused by a chromosomal abnormality. Choice B is incorrect as the condition is not linked to a single segment found only on the Y chromosome. Choice D is unrelated as it mentions a decrease in estrogen levels, which is not a cause of sickle-cell anemia.

Correct Answer: C

Rationale: Teratogens are environmental agents, such as drugs, chemicals, or infections, that can cause harm to a developing embryo or fetus. Mutations (Choice A) refer to changes in the DNA sequence and are not environmental agents. Autosomes (Choice B) are chromosomes that are not involved in determining an individual's sex and are not environmental agents that harm the embryo or fetus. Androgens (Choice D) are a group of hormones that are more related to male sexual development and function, not environmental agents that harm the embryo or fetus.