Nokea
What is the purpose of the ovum’s zona pellucida?
- A. Prevents multiple sperm from fertilizing the ovum
- B. Stimulates the ovum to begin mitotic cell division
- C. Allows the 46 chromosomes from each gamete to merge
- D. Makes a pathway for more than one sperm to reach the ovum
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.
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The nurse is planning a prenatal class on fetal development. Which characteristics of prenatal development should the nurse include for a fetus of 24 weeks, based on fertilization age? (Select all that apply.)
- A. Ear cartilage firm
- B. Skin wrinkled and red
- C. Testes descending toward the inguinal rings
- D. Surfactant production nears mature levels
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.
The nurse is providing genetic counseling for an expectant couple who already have a child with trisomy 18. The nurse should:
- A. Tell the couple they need to have an abortion within 2 to 3 weeks.
- B. Explain that the fetus has a 50% chance of having the disorder.
- C. Discuss options with the couple, including amniocentesis to determine whether the fetus is affected.
- D. Refer the couple to a psychologist for emotional support.
Correct Answer: C
Rationale: Genetic testing, including amniocentesis, would need to be performed to determine whether the fetus is affected.
The nurse caring for a pregnant patient knows that her health teaching regarding fetal circulation has been effective when the patient reports that she has been sleeping:
- A. In a side-lying position.
- B. On her back with a pillow under her knees.
- C. With the head of the bed elevated.
- D. On her abdomen.
Correct Answer: A
Rationale: Optimal circulation is achieved when the woman is lying at rest on her side.
The nurse explains to the patient at 28 weeks’ gestation not to lie flat on their back during the remainder of the pregnancy. What does this precaution prevent?
- A. acid reflux
- B. headaches
- C. pregnancy-induced hypertension
- D. vena cava syndrome
Correct Answer: D
Rationale: Lying flat can compress the vena cava, leading to reduced blood flow. Other options are unrelated.
The nurse works in an infertility clinic and is interviewing a male patient whose partner has been unable to conceive. Which finding obtained during a health history will cause the nurse greatest concern?
- A. The patient is a passionate gardener.
- B. The patient had a vasectomy reversed.
- C. The patient rides a bicycle daily to work.
- D. The patient is concerned about infertility.
Correct Answer: B
Rationale: A vasectomy reversal can lead to the development of antibodies that reduce sperm motility, impacting fertility.