1. Which part of the heart generates the QRS complex on an ECG?

A. Sinoatrial node (SA node)
B. Atrioventricular node (AV node)
C. Bundle of His
D. Ventricular muscle cells

Correct answer: D

Rationale: The correct answer is D, ventricular muscle cells. The QRS complex on an ECG represents the depolarization of the ventricles. This electrical activity is generated by the spread of impulses through the bundle branches and Purkinje fibers to the ventricular muscle cells. The SA node (option A) is responsible for initiating the electrical impulse in the heart, but it does not directly generate the QRS complex. The AV node (option B) delays the impulse to allow for proper coordination of atrial and ventricular contractions. The Bundle of His (option C) and its branches facilitate the conduction of the electrical signal from the AV node to the ventricles but do not generate the QRS complex directly.

2. The process of a gas changing directly into a solid is called:

A. Condensation
B. Deposition
C. Sublimation
D. Evaporation

Correct answer: B

Rationale: This process, also known as sublimation, involves gas particles losing energy and transitioning directly into the solid state.

3. 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.

4. A child's toy block is a cube with side lengths of 5cm. What is its total surface area?

A. 25 sq cm
B. 50 sq cm
C. 125 sq
D. 150 sq cm

Correct answer: D

Rationale: Use the formula for surface area of a cube: 6 * (side length)^2 = 6 * (5cm)^2 = 125 sq cm.

5. What is the term for the inflammation of the airways in the lungs, often causing wheezing and difficulty breathing?

A. Pneumonia
B. Emphysema
C. Asthma
D. Pleurisy

Correct answer: C

Rationale: The correct answer is C: "Asthma." Asthma is a chronic condition characterized by inflammation of the airways in the lungs, leading to symptoms like wheezing, shortness of breath, coughing, and chest tightness. Pneumonia (A) is an infection in the lungs caused by bacteria, viruses, or fungi. Emphysema (B) is a type of chronic obstructive pulmonary disease (COPD) characterized by damage to the air sacs in the lungs. Pleurisy (D) is inflammation of the lining of the lungs and chest cavity. Therefore, asthma best fits the description provided in the question, making it the correct answer.

6. Which of the following is NOT a mechanism of evolution?

A. Natural selection
B. Genetic drift
C. Lamarckism
D. Mutation

Correct answer: C

Rationale: Rationale: A) Natural selection is a mechanism of evolution where individuals with advantageous traits are more likely to survive and reproduce, passing on those traits to the next generation. B) Genetic drift is a mechanism of evolution that occurs due to random changes in allele frequencies in a population. C) Lamarckism, also known as the inheritance of acquired characteristics, is a discredited theory that suggests organisms can pass on traits acquired during their lifetime to their offspring. This mechanism has been largely rejected by the scientific community. D) Mutation is a mechanism of evolution that introduces new genetic variation into a population, which can lead to the emergence of new traits and adaptations over time.