Which of the following pairs of bases is present in the rungs of the ladder-like structure of deoxyribonucleic acid (DNA)?
- A. Cytosine with guanine.
- B. Rhodamine with biotin.
- C. Diaminopurine with ribozyme.
- D. Serine with tyrosine.
Correct Answer: A
Rationale: The correct answer is A: Cytosine with guanine. In the DNA double helix, cytosine always pairs with guanine forming a base pair, and adenine pairs with thymine. These complementary base pairs form the rungs of the ladder-like structure of DNA. Choice B, Rhodamine with biotin, is incorrect as they are not base pairs found in DNA. Choice D, Serine with tyrosine, is incorrect as they are amino acids, not DNA bases. Choice C, Diaminopurine with ribozyme, is also incorrect as ribozyme is an enzyme, not a base, and diaminopurine is not one of the standard bases found in DNA.
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When should a nurse on a labor and delivery unit instruct a newly licensed nurse to don gloves for a procedure?
- A. Assisting a mother with breastfeeding
- B. Performing a newborn's initial bath
- C. Administering the measles, mumps, rubella vaccine
- D. Performing umbilical cord care
Correct Answer: B
Rationale: The correct answer is B: Performing a newborn's initial bath. Gloves should be worn during this procedure to protect against exposure to body fluids, such as amniotic fluid or blood. Assisting a mother with breastfeeding (Choice A) does not typically require gloves unless there are specific reasons for infection control. Administering vaccines (Choice C) and performing umbilical cord care (Choice D) are procedures that may require hand hygiene but not necessarily gloves, unless there is active bleeding or potential exposure to body fluids. The initial bath involves direct contact with body fluids, making it crucial to wear gloves for protection.
A 25-year-old gravida 3, para 2 client gave birth to a 9-pound, 7-ounce boy 4 hours ago after augmentation of labor with oxytocin (Pitocin). She presses her call light and asks for her nurse right away, stating 'I'm bleeding a lot.' What is the most likely cause of postpartum hemorrhage in this client?
- A. Retained placental fragments.
- B. Unrepaired vaginal lacerations.
- C. Uterine atony.
- D. Puerperal infection.
Correct Answer: C
Rationale: Uterine atony is the most likely cause of bleeding 4 hours after delivery, especially after delivering a macrosomic infant and augmenting labor with oxytocin. Uterine atony is characterized by the inability of the uterine muscles to contract effectively after childbirth, leading to excessive bleeding. The other options, such as retained placental fragments (A), unrepaired vaginal lacerations (B), and puerperal infection (D), are less likely causes of postpartum hemorrhage in this scenario. Retained placental fragments can cause bleeding, but this typically presents earlier than 4 hours postpartum. Unrepaired vaginal lacerations would likely be evident sooner and not typically result in significant bleeding. Puerperal infection is not a common cause of immediate postpartum hemorrhage unless there are other signs of infection present.
Tim, a 27-year-old man, has unusually narrow shoulders, low muscle mass, and has no facial and body hair. His doctor recently prescribed testosterone replacement therapy to him. Tim is most likely suffering from:
- A. Phenylketonuria (PKU).
- B. Cystic fibrosis.
- C. Klinefelter syndrome.
- D. Huntington's disease (HD).
Correct Answer: C
Rationale: Tim's physical characteristics, such as narrow shoulders, low muscle mass, and lack of facial and body hair, are typical signs of Klinefelter syndrome, a genetic condition where males have an extra X chromosome (XXY). This leads to underdeveloped testes and reduced testosterone production, resulting in features like gynecomastia, sparse facial and body hair, and reduced muscle mass. Testosterone replacement therapy is commonly used to address the hormonal imbalance in individuals with Klinefelter syndrome. Phenylketonuria (PKU) is a metabolic disorder unrelated to the symptoms described in Tim's case. Cystic fibrosis is a genetic respiratory condition that does not present with the physical characteristics mentioned. Huntington's disease (HD) is a neurodegenerative disorder primarily affecting motor function and cognition, not physical appearance and muscle mass.
During which of the following periods does the development of arms and legs occur in a pregnancy?
- A. Development of the lungs
- B. Development of the heart
- C. Development of arms and legs
- D. Development of the stomach
Correct Answer: C
Rationale: The correct answer is C. The development of arms and legs occurs during the critical period of the fourth to eighth weeks of pregnancy. This timeframe is crucial for the formation of limbs and other key body parts. Choices A, B, and D are incorrect because the development of the lungs, heart, and stomach respectively occurs at different stages of fetal development and is not primarily associated with the fourth to eighth weeks of pregnancy.
A nurse is caring for a newborn who is 6 hours old and has a bedside glucometer reading of 65 mg/dL. The newborn's mother has type 2 diabetes mellitus. Which of the following actions should the nurse take?
- A. Obtain a blood sample for a serum glucose level
- B. Feed the newborn immediately
- C. Administer 50 mL of dextrose solution IV
- D. Reassess the blood glucose level prior to the next feeding
Correct Answer: D
Rationale: A bedside glucometer reading of 65 mg/dL is within the normal range for a newborn. Reassessing the blood glucose level prior to the next feeding ensures ongoing monitoring without unnecessary intervention. Obtaining a blood sample for a serum glucose level (Choice A) is not necessary as the initial reading is normal. Feeding the newborn immediately (Choice B) may not be indicated and could lead to unnecessary interventions. Administering dextrose solution IV (Choice C) is not warranted as the glucose level is within the normal range and does not require immediate correction.