A 34-year-old patient who is 16 weeks pregnant had a multiple markers screening done. The results came back with an increased risk for trisomy 21. You call the patient to go over the results. How should you respond when the patient asks you if the baby is going to have Down syndrome?

Correct Answer: B

Rationale: Screening tests like multiple marker tests indicate risk but do not confirm a diagnosis. Further tests are needed to determine if the baby has Down syndrome.

Correct Answer: A

Rationale: The ectoderm forms the nervous system, along with the skin and sensory organs.

Correct Answer: D

Rationale: Carrier screening identifies genetic disorders parents may carry, which can affect the baby. It does not check positioning, heart rate, or chromosomal abnormalities directly.

Correct Answer: A

Rationale: A. Ear cartilage firm: By 24 weeks, the fetus's ear cartilage has developed and become firm, allowing the ears to be more defined in shape.

Correct Answer: A

Rationale: The zona pellucida is a protective layer surrounding the ovum (egg cell). One of its primary functions is to prevent multiple sperm from fertilizing the egg by only allowing one sperm to penetrate and fertilize the ovum. This is crucial for ensuring that the resulting embryo has the correct genetic material (46 chromosomes) and does not have an abnormal number of chromosomes, which could lead to developmental issues. The zona pellucida acts as a physical barrier that helps to maintain the genetic integrity of the offspring.