Nursing Elites

1. The Gram stain is a differential staining technique used to classify bacteria based on their cell wall composition. Gram-positive bacteria appear

• A. Pink
• B. Blue
• C. Red
• D. Purple

Correct answer: D

Rationale: Rationale: The Gram stain is a differential staining technique that divides bacteria into two groups based on their cell wall composition: Gram-positive and Gram-negative. Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which retains the crystal violet stain used in the Gram staining procedure. As a result, Gram-positive bacteria appear purple under the microscope after staining. In contrast, Gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane that can be penetrated by the counterstain safranin, causing them to appear pink or red. Blue is not typically used to describe the color of bacteria in a Gram stain.

2. The ability of optical fibers to transmit light signals around bends is primarily due to:

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Polarization

Correct answer: B

Rationale: The correct answer is B: Refraction. Optical fibers transmit light signals around bends primarily through the process of refraction. Refraction occurs when light passes from one medium to another, causing it to change direction. In optical fibers, the core material has a higher refractive index than the cladding, which causes light to be reflected internally along the fiber. This phenomenon allows light signals to travel through the fiber even around bends without significant loss. Reflection (Option A) involves light bouncing off a surface, which is not the main mechanism in optical fibers. Diffraction (Option C) refers to the bending of light waves around obstacles and is not the main reason for light transmission in optical fibers. Polarization (Option D) relates to the orientation of light waves, which is not the primary factor enabling light transmission around bends in optical fibers.

3. Which of the following is NOT typically found in healthy urine?

• A. Urea
• B. Glucose
• C. Creatinine
• D. Electrolytes

Correct answer: B

Rationale: Glucose is NOT typically found in healthy urine because the kidneys filter glucose from the blood, and any excess is excreted in the urine. In healthy individuals, the renal threshold for glucose reabsorption is low, so glucose should not be present in significant amounts in urine. On the other hand, urea, creatinine, and electrolytes are all normal components of urine. Urea is a waste product of protein metabolism, creatinine is a waste product of muscle metabolism, and electrolytes like sodium and potassium are essential for various bodily functions and are excreted in urine. Therefore, option B is the correct answer as glucose is not typically found in healthy urine.

4. A lampshade is shaped like a frustum of a cone, with base diameters of 20cm and 10cm and a height of 15cm. What is its volume?

• A. 625 cu cm
• B. 1250 cu cm
• C. 1875 cu cm
• D. 2500 cu cm

Correct answer: C

Rationale: This requires dividing the frustum into two cones and calculating their individual volumes before subtracting them. The formula for a cone frustum involves the radii of both bases and the height.

5. A person is pushing a box across the floor. Which of the following forces is NOT doing work?

• A. The person's pushing force
• B. The normal force from the floor
• C. The gravitational force on the box
• D. The frictional force between the box and the floor

Correct answer: A

Rationale: Work is defined as the force applied in the direction of motion multiplied by the distance moved. Since the normal force acts perpendicular to the motion, it does not contribute to work.

6. In which part of the cell are proteins modified, sorted, and packaged for transport?

• A. Ribosomes
• B. Golgi apparatus
• C. Endoplasmic reticulum (ER)
• D. Lysosomes

Correct answer: B

Rationale: The Golgi apparatus is responsible for modifying, sorting, and packaging proteins for transport. After proteins are synthesized in the rough endoplasmic reticulum (ER), they are transported to the Golgi apparatus where they undergo post-translational modifications and are sorted into vesicles for transport to their final destinations. Ribosomes are responsible for protein synthesis, the endoplasmic reticulum is involved in protein synthesis and folding, and lysosomes are responsible for digesting cellular waste. Therefore, the correct answer is B, Golgi apparatus, as it is specifically involved in the modification, sorting, and packaging of proteins for transport.

Similar Questions