1. The human body's command center, integrating sensory information and coordinating movement and vital functions, is the:

A. Lungs
B. Brain
C. Kidneys
D. Stomach

Correct answer: B

Rationale: The correct answer is B: Brain. The brain serves as the command center of the human body, receiving sensory information from various parts of the body and coordinating responses. It is responsible for controlling movement, regulating vital functions such as breathing and heart rate, and processing thoughts and emotions. The lungs (A), kidneys (C), and stomach (D) each have specific functions within the body, but they do not serve as the central command center like the brain does. Therefore, the brain is the correct answer to this question.

2. What is the formula for calculating density?

A. Density = Volume / Mass
B. Density = Mass Ãƒâ€” Volume
C. Density = Mass / Volume
D. Density = Volume - Mass

Correct answer: c

Rationale: Density is defined as the mass of a substance divided by its volume. The formula for density is Density = Mass / Volume.

3. According to Newton's third law of motion, for every action, there is an equal and opposite ___________.

A. Reaction
B. Force
C. Acceleration
D. Momentum

Correct answer: a

Rationale: Newton's third law states that for every force or action, there is an equal and opposite reaction.

4. Why are isotopes of the same element chemically similar?

A. They have the same number of protons.
B. They have the same number of electrons.
C. Their chemical properties are identical.
D. They share the same electron configuration.

Correct answer: A

Rationale: They have the same number of protons. This determines the element's identity and its interactions with other elements, leading to similar chemical behavior, even if the number of neutrons differs.

5. Which of the following is the main function of the small intestine?

A. To store food and break it down into smaller pieces
B. To absorb nutrients into the bloodstream
C. To produce enzymes that help digest food
D. To eliminate waste products from the body

Correct answer: B

Rationale: Rationale: The small intestine is a crucial part of the digestive system where the majority of nutrient absorption takes place. It is lined with tiny finger-like projections called villi that increase the surface area for absorption. The small intestine absorbs nutrients such as carbohydrates, proteins, fats, vitamins, and minerals from the digested food into the bloodstream to be transported to cells throughout the body for energy, growth, and repair. Options A, C, and D do not accurately describe the main function of the small intestine.

6. Muscle soreness after exercise is often caused by microscopic tears in muscle fibers. This is called

A. Atrophy
B. Hypertrophy
C. Dom (Delayed Onset Muscle Soreness)
D. Spasm

Correct answer: C

Rationale: Muscle soreness after exercise is commonly caused by microscopic tears in muscle fibers, leading to a condition known as Delayed Onset Muscle Soreness (DOMS). Atrophy refers to the shrinking of muscle due to inactivity or lack of use, which is not the cause of muscle soreness after exercise. Hypertrophy is the increase in muscle size through exercise, not related to muscle soreness. Spasm is a sudden, involuntary muscle contraction unrelated to the micro-tears that cause muscle soreness. Therefore, the correct answer is C, DOMS, as it specifically addresses the micro-tears in muscle fibers that result in post-exercise soreness.