1. Dietary fiber, although not fully digested by the body, plays a crucial role in digestion. What is one of the main benefits of consuming sufficient dietary fiber?

A. Provides a concentrated source of energy
B. Aids in the absorption of vitamins and minerals
C. Promotes satiety and gut health
D. Breaks down complex carbohydrates

Correct answer: C

Rationale: Consuming sufficient dietary fiber promotes satiety and gut health. Fiber adds bulk to the diet, which helps you feel full and satisfied after meals, reducing overeating. Additionally, fiber helps regulate bowel movements by promoting healthy digestion and preventing constipation. It also feeds beneficial gut bacteria, supporting a healthy gut microbiome. While fiber does not provide energy like carbohydrates, it is essential for overall digestive health and can help prevent various chronic diseases.

2. Which condition involves an overactive immune system attacking healthy tissues, leading to inflammation and damage?

A. Immunodeficiency
B. Autoimmune disease
C. Allergy
D. Cancer

Correct answer: B

Rationale: The correct answer is B: Autoimmune disease. Autoimmune diseases occur when the immune system mistakenly attacks healthy cells and tissues in the body, leading to inflammation and damage. Immunodeficiency (option A) is the opposite, where the immune system is weakened or not functioning properly. Allergies (option C) involve the immune system overreacting to harmless substances. Cancer (option D) is characterized by uncontrolled cell growth, not by the immune system attacking healthy tissues.

3. The T wave on an ECG corresponds to:

A. Atrial depolarization
B. Ventricular depolarization
C. Atrial repolarization
D. Ventricular repolarization

Correct answer: D

Rationale: The T wave on an ECG corresponds to ventricular repolarization. During this phase, the ventricles are resetting electrically after contraction, preparing for the next heartbeat. Atrial depolarization is represented by the P wave, ventricular depolarization by the QRS complex, and atrial repolarization is typically hidden within the QRS complex. Therefore, option D, 'Ventricular repolarization,' is the correct choice when identifying the electrical activity represented by the T wave on an ECG.

4. The moon-shaped white structures at the base of fingernails are called:

A. Lunulae
B. Cuticle
C. Hyponychium
D. Matrix

Correct answer: A

Rationale: The correct answer is A, "Lunulae." The moon-shaped white structures at the base of fingernails are called lunulae. These are most visible on the thumb and are the visible part of the nail matrix. The lunulae appear white because the nail matrix underneath is not visible due to its thickness. Cuticle (B) refers to the thin layer of skin at the base of the nail, hyponychium (C) is the skin located under the free edge of the nail, and matrix (D) is the tissue at the base of the nail where growth occurs. Therefore, the correct term for the moon-shaped white structures is lunulae.

5. What is the difference between a sensory neuron and a motor neuron?

A. Sensory neurons carry signals away from the brain, while motor neurons carry signals towards the brain.
B. Sensory neurons control voluntary muscles, while motor neurons control involuntary muscles.
C. Sensory neurons are located in the peripheral nervous system, while motor neurons are located in the central nervous system.
D. Sensory neurons detect light, while motor neurons detect sound.

Correct answer: A

Rationale: The correct answer is A because sensory neurons are responsible for carrying signals from sensory receptors towards the central nervous system (brain and spinal cord), allowing us to perceive sensations such as touch, taste, smell, sight, and sound. On the other hand, motor neurons carry signals from the central nervous system to muscles and glands, enabling movement and responses. Therefore, sensory neurons carry signals away from the brain, while motor neurons carry signals towards the brain, making option A the most accurate choice among the options provided.

6. Long-term potentiation (LTP) is a process in the brain associated with:

A. Sensory perception
B. Memory formation
C. Muscle control
D. Emotional regulation

Correct answer: D

Rationale: Long-term potentiation (LTP) is a process in the brain that is primarily associated with memory formation. During LTP, the strength of synaptic connections between neurons is increased, which is crucial for encoding and storing memories. While sensory perception, muscle control, and emotional regulation involve different brain processes, LTP specifically plays a key role in the formation and retention of memories. Therefore, the correct answer is B: Memory formation.