HESI RN
Biology Test
1. What are the nitrogenous bases of DNA?
- A. Adenine, cytosine, guanine, and thymine
- B. Adenine, guanine, and uracil
- C. Adenine, guanine, and thymine
- D. Adenine, cytosine, guanine, and uracil
Correct answer: A
Rationale: The correct answer is A: Adenine, cytosine, guanine, and thymine. These are the four nitrogenous bases found in DNA. Adenine pairs with thymine, and cytosine pairs with guanine, forming the complementary base pairs in the double helix structure of DNA. Choice B is incorrect because uracil is a nitrogenous base found in RNA, not DNA. Choice C is incorrect as it is missing cytosine, one of the four bases in DNA. Choice D is incorrect because uracil is not a nitrogenous base in DNA, and it also lacks thymine, which is essential for DNA structure.
2. An older client who had a subtotal parathyroidectomy is preparing for discharge. What finding requires immediate provider notification?
- A. Afebrile with a normal pulse.
- B. No bowel movement since surgery.
- C. No appetite for breakfast.
- D. A positive Chvostek's sign.
Correct answer: D
Rationale: A positive Chvostek's sign indicates hypocalcemia, a complication after parathyroid surgery that requires immediate attention. This sign is manifested by facial muscle twitching when the facial nerve in front of the ear is tapped, indicating neuromuscular irritability due to low calcium levels. Afebrile with a normal pulse (Choice A) is a normal finding and does not require immediate notification. No bowel movement since surgery (Choice B) is common postoperatively due to anesthesia effects and pain medications and usually resolves within a few days; it does not require immediate notification unless accompanied by other concerning symptoms. No appetite for breakfast (Choice C) is a common postoperative finding and does not require immediate notification unless it persists and leads to dehydration or malnutrition.
3. The nurse is preparing to administer an IM injection to a 6-month-old child. Which injection site is best for the nurse to use?
- A. Vastus lateralis
- B. Deltoid
- C. Ventrogluteal
- D. Dorsogluteal
Correct answer: A
Rationale: The vastus lateralis is the preferred site for IM injections in infants due to muscle development. In infants under 1 year old, the vastus lateralis muscle in the thigh is often used for IM injections due to its size and development. The deltoid muscle is typically used for adults, and the ventrogluteal and dorsogluteal sites are more commonly used for older children and adults. Therefore, the best choice for administering an IM injection to a 6-month-old child is the vastus lateralis.
4. When preparing a client for intravenous pyelography (IVP), which action by the nurse is most important?
- A. Administering a sedative
- B. Encouraging fluid intake
- C. Administering an oral preparation of radiopaque dye
- D. Questioning the client about allergies to iodine or shellfish
Correct answer: D
Rationale: The most crucial action for the nurse when preparing a client for intravenous pyelography (IVP) is to question the client about allergies to iodine or shellfish. Some IVP dyes contain iodine, and if the client is allergic to iodine or shellfish, they may experience severe allergic reactions such as itching, hives, rash, throat tightness, difficulty breathing, or bronchospasm. Administering a sedative (Choice A) may be needed for relaxation during the procedure, encouraging fluid intake (Choice B) is generally beneficial but not the most crucial for IVP preparation, and administering radiopaque dye (Choice C) should only be done after confirming the client's safety regarding allergies to iodine or shellfish.
5. Which technique is used to detect HIV/AIDS?
- A. Northern blot and ELISA
- B. Immunoblot and ELISA
- C. Western blot and ELISA
- D. Southern blot and ELISA
Correct answer: C
Rationale: The correct answer is C: Western blot and ELISA. Western blot and ELISA are commonly used techniques in the detection of HIV/AIDS. Western blot is used to confirm the presence of HIV antibodies in a patient's blood after an initial positive ELISA test. Northern blotting is a technique used for RNA analysis, not for detecting HIV/AIDS (Choice A). Immunoblotting is another term for Western blotting, so Choice B is incorrect. Southern blotting is used for DNA analysis, not for detecting HIV/AIDS (Choice D).