1. What is the difference between isometric and isotonic muscle contractions?

A. Isometric involves movement, while isotonic does not.
B. Isotonic involves shortening of muscle, while isometric maintains length.
C. Isometric uses more energy, while isotonic uses less.
D. Isotonic involves smooth muscle, while isometric involves skeletal muscle.

Correct answer: B

Rationale: The correct answer is B: "Isotonic involves shortening of muscle, while isometric maintains length." Isometric contractions occur when the muscle generates force without changing its length, such as holding a weight in a fixed position. On the other hand, isotonic contractions involve the muscle changing length, either by shortening (concentric contraction) or lengthening (eccentric contraction) while generating force. Understanding this distinction is crucial for grasping the different types of muscle contractions and their effects on the body during exercise and movement.

2. The involuntary reflex arc that withdraws your hand from a hot object involves the:

A. Central nervous system only
B. Peripheral nervous system only
C. Both CNS and PNS
D. Sensory neurons only

Correct answer: C

Rationale: The correct answer is C: 'Both CNS and PNS'. This is because the reflex arc involves both the central nervous system (CNS) and the peripheral nervous system (PNS). The sensory neurons in the PNS detect the stimulus (hot object), then send signals to the spinal cord in the CNS. The spinal cord processes the information and immediately sends a motor response signal back out through the PNS to move the hand away from the hot object. This rapid and involuntary response demonstrates the coordination between the CNS and PNS in executing the reflex arc.

3. What is the name for the balanced equation that represents a chemical reaction?

A. Hypothesis
B. Chemical formula
C. Balanced equation
D. Reaction mechanism

Correct answer: C

Rationale: A balanced equation shows the reactants, products, and their stoichiometric coefficients, ensuring equal numbers of atoms of each element on both sides.

4. Recognize the opposing muscle pair.

A. Bicep and tricep (Arm flexion and extension)
B. Hamstring and quadriceps (Knee extension and flexion)
C. Pectoralis major and pectoralis minor (Chest muscles)
D. Trapezius and deltoid (Shoulder movement)

Correct answer: A

Rationale: The bicep and tricep muscles are antagonistic muscle pairs, meaning they work in opposition to each other. The bicep is located on the front of the upper arm and is responsible for flexing the elbow joint. The tricep is located on the back of the upper arm and is responsible for extending the elbow joint.

5. The involuntary "fight-or-flight" response is controlled by the:

A. Sympathetic nervous system
B. Parasympathetic nervous system
C. Enteric nervous system
D. Sensory nervous system

Correct answer: A

Rationale: The correct answer is A: Sympathetic nervous system. The "fight-or-flight" response is an automatic physiological reaction triggered by the sympathetic nervous system in response to a perceived threat or stressor. This system prepares the body for action by increasing heart rate, dilating pupils, and redirecting blood flow to muscles. The parasympathetic nervous system, on the other hand, controls the body's "rest-and-digest" response, promoting relaxation and digestion. The enteric nervous system primarily regulates the gastrointestinal system, while the sensory nervous system is responsible for transmitting sensory information to the brain. Therefore, the sympathetic nervous system is specifically responsible for initiating the fight-or-flight response.

6. When water boils, it changes from a liquid to a gas. This is an example of a:

A. Chemical reaction
B. Physical change
C. Nuclear reaction
D. Biological process

Correct answer: B

Rationale: Physical change - Boiling water involves a change in state, not the chemical composition of the molecules. Chemical reactions involve breaking and forming new bonds, which is not the case here.