Nursing Elites

1. Which level of protein structure is defined by the folds and coils of the protein's polypeptide backbone?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary

Correct answer: B

Rationale: The correct answer is B: Secondary. The secondary structure of a protein is defined by the folds and coils of the protein's polypeptide backbone. This level of structure is characterized by the formation of alpha helices and beta sheets, which are stabilized by hydrogen bonds between amino acids along the polypeptide chain. Choice A, Primary, refers to the linear sequence of amino acids in the protein. Choice C, Tertiary, involves the 3D folding of the entire polypeptide chain. Choice D, Quaternary, pertains to the arrangement of multiple polypeptide subunits in a protein complex.

2. Which of the following is NOT a component of the genitourinary system?

• A. The kidneys
• B. The urethra
• C. The rectum
• D. The bladder

Correct answer: C

Rationale: The rectum is part of the digestive system, not the genitourinary system. The genitourinary system comprises organs involved in reproduction and urine formation and excretion, such as the kidneys, urethra, and bladder. Choices A, B, and D are all components of the genitourinary system. The kidneys filter blood and produce urine, the urethra is a tube that carries urine from the bladder out of the body, and the bladder stores urine before it is excreted.

3. Which structure in the ear is responsible for maintaining balance?

• A. Cochlea
• B. Semicircular canals
• C. Eardrum
• D. Auditory nerve

Correct answer: B

Rationale: The correct answer is the semicircular canals. These structures in the inner ear are responsible for maintaining balance and equilibrium by detecting rotational movements of the head. The cochlea is responsible for hearing as it contains the sensory cells for detecting sound vibrations, the eardrum is a membrane that transmits sound waves to the middle ear, and the auditory nerve carries sound signals from the cochlea to the brain for processing. Therefore, choices A, C, and D are incorrect as they are not primarily associated with maintaining balance.

4. Which structure in the female reproductive system is responsible for producing eggs (ova)?

• A. Fallopian tubes
• B. Ovaries
• C. Uterus
• D. Vagina

Correct answer: B

Rationale: The correct answer is the ovaries. Ovaries are the primary reproductive organs in females responsible for producing eggs (ova) through a process known as oogenesis. Ova are released from the ovaries during ovulation and can be fertilized by sperm in the fallopian tubes. The uterus is where a fertilized egg implants and develops into a fetus, while the vagina serves as the birth canal and a site for sexual intercourse. Fallopian tubes are responsible for transporting eggs from the ovaries to the uterus and are the site where fertilization typically occurs. Therefore, while important for the reproductive process, the fallopian tubes do not produce eggs.

5. A light ray travels from air (refractive index 1.00) into water (refractive index 1.33). What happens to its speed and direction?

• A. Speed increases, direction bends towards the normal.
• B. Speed increases, direction bends away from the normal.
• C. Speed decreases, direction bends towards the normal.
• D. Speed and direction remain unchanged.

Correct answer: C

Rationale: When a light ray travels from air (lower refractive index) to water (higher refractive index), its speed decreases due to the change in the medium. This is because light travels slower in denser mediums. As the light ray enters the denser medium, water in this case, it bends towards the normal (the line perpendicular to the surface of the water). This phenomenon is known as refraction. Choice A is incorrect as the speed of light decreases when entering a denser medium. Choice B is incorrect as the direction bends towards the normal, not away from it. Choice D is incorrect as the speed and direction of the light ray do change when moving from air to water.

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