Nursing Elites

1. Which term refers to a molecule of DNA and structural protein?

• A. Lysosome
• B. Centrosome
• C. Chromosome
• D. Genome

Correct answer: C

Rationale: The correct answer is C: Chromosome. A chromosome is a structure composed of DNA and proteins that carries genetic information. It is the condensed form of DNA associated with structural proteins, not just a molecule of DNA or protein. Lysosomes are membrane-bound organelles containing digestive enzymes, not DNA and protein. Centrosomes are involved in cell division, not related to DNA and protein together. A genome refers to an organism's complete set of DNA, not specifically a molecule containing both DNA and structural protein.

2. What is the role of the large intestine in the digestive system?

• A. To break down proteins
• B. To absorb water and form feces
• C. To digest fats
• D. To neutralize stomach acid

Correct answer: B

Rationale: The correct answer is B. The large intestine plays a crucial role in absorbing water from indigestible food matter and forming feces for elimination. Choice A is incorrect because the breakdown of proteins primarily occurs in the stomach and small intestine. Choice C is incorrect as the digestion of fats primarily occurs in the small intestine. Choice D is incorrect as neutralizing stomach acid is mainly the function of the stomach lining and not the large intestine.

3. What is the structural and functional unit of the kidney responsible for filtering blood?

• A. Nephron
• B. Ureter
• C. Urethra
• D. Bladder

Correct answer: A

Rationale: The nephron is the correct answer. It is the structural and functional unit of the kidney responsible for filtering blood. The nephron consists of a renal corpuscle (glomerulus and Bowman's capsule) and a renal tubule. Within the nephron, blood is filtered to form urine, which is then carried to the ureter for excretion from the body. Choices B, C, and D are incorrect because the ureter, urethra, and bladder are not involved in the filtration of blood in the kidney. Instead, they are parts of the urinary system responsible for transporting and storing urine.

4. Homologous structures are those that:

• A. Have the same function but different origins
• B. Have different functions but the same origin
• C. Are similar in appearance and function due to shared ancestry
• D. Are identical in both appearance and function

Correct answer: C

Rationale: Homologous structures are defined as anatomical features that are similar in appearance and function due to shared ancestry. This means that these structures are inherited from a common ancestor and may have evolved to fulfill different functions in different species. Option A, which mentions structures with the same function but different origins, describes analogous structures, not homologous ones. Option B, which refers to structures with different functions but the same origin, actually characterizes vestigial structures. Option D, stating that structures are identical in appearance and function, does not necessarily imply homology; such structures could result from convergent evolution rather than shared ancestry. Understanding homologous structures provides insights into the evolutionary relationships between different species and supports the concept of common descent.

5. A car is moving in a circle at a constant speed. Which of the following is NOT true about its motion?

• A. It has a constant centripetal acceleration
• B. Its tangential velocity remains constant
• C. It experiences a force directed towards the center of the circle
• D. It covers the same distance in equal time intervals along its circular path

Correct answer: B

Rationale: In circular motion at a constant speed, the car has a constant centripetal acceleration (choice A), experiences a force directed towards the center of the circle (choice C), and covers the same distance in equal time intervals along its circular path (choice D). However, the tangential velocity of an object in circular motion at a constant speed changes continuously as it moves around the circle, so it is not constant (choice B). The change in tangential velocity allows the car to maintain its motion in a circular path despite moving at a constant speed. Choice A is incorrect because centripetal acceleration is indeed present to keep the car moving in a circular path. Choice C is incorrect as a force towards the center is required to keep the car in circular motion. Choice D is incorrect because the car covers equal distances in equal time intervals to maintain its circular trajectory.

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