1. What is a lifestyle practice that can weaken the immune system?

A. Getting enough sleep
B. Eating a balanced diet rich in fruits and vegetables
C. Managing stress levels
D. Frequent smoking

Correct answer: D

Rationale: Frequent smoking is a lifestyle practice that can weaken the immune system. Smoking has been linked to various health issues, including suppressing the immune system's ability to fight off infections and diseases. The chemicals in tobacco smoke can impair immune function, making smokers more susceptible to illnesses. On the other hand, getting enough sleep, eating a balanced diet rich in fruits and vegetables, and managing stress levels are practices that support a healthy immune system, rather than weaken it.

2. A ball is thrown horizontally off a cliff with a speed of 10 m/s. What is the horizontal distance the ball travels before hitting the ground?

A. 10 m
B. 20m
C. 30m
D. Cannot be determined without knowing the height of the cliff

Correct answer: C

Rationale: When a ball is thrown horizontally, its horizontal velocity remains constant throughout its motion. The time taken to hit the ground is determined by the vertical motion, which is independent of the horizontal velocity. Therefore, the horizontal distance traveled by the ball is determined by the horizontal velocity and the time taken to hit the ground. In this case, the horizontal distance is calculated as distance = velocity Ã— time = 10 m/s Ã— time. Since the horizontal velocity is 10 m/s and the time taken to hit the ground is determined by the vertical motion, the horizontal distance traveled by the ball is 10 m/s Ã— time. Without knowing the height of the cliff, we can still determine the horizontal distance traveled by the ball, which is 10 m/s Ã— time.

3. Which element shares the same group (family) on the periodic table with helium (He)?

A. Neon (Ne)
B. Boron (B)
C. Carbon (C)
D. Oxygen (O)

Correct answer: A

Rationale: Neon (Ne). Both He and Ne belong to Group 18 (Noble Gases) due to their complete and stable outer electron shells.

4. Which protein complex in the sarcomere is responsible for the thick filament?

A. Actin
B. Myosin
C. Tropomyosin
D. Troponin

Correct answer: B

Rationale: The correct answer is B: Myosin. In the sarcomere, the thick filament is composed of myosin protein. Myosin is responsible for the interaction with actin filaments during muscle contraction, forming cross-bridges that generate the force required for muscle movement. Actin (choice A) is a component of the thin filament in the sarcomere, while tropomyosin (choice C) and troponin (choice D) are regulatory proteins associated with muscle contraction but are not part of the thick filament. Understanding the specific components of the sarcomere is crucial for comprehending muscle contraction mechanisms.

5. What is the Pauli exclusion principle?

A. The principle that electrons fill orbitals in order of increasing energy.
B. The principle that electrons cannot be in the same orbital with the same spin.
C. The principle that the maximum number of electrons in an orbital is 2n^2, where n is the energy level of the orbital.
D. The principle that the attractive force between an electron and the nucleus is inversely proportional to the distance between them.

Correct answer: B

Rationale: The Pauli exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers. This means that electrons in the same orbital must have opposite spins, which is why they cannot be in the same orbital with the same spin. Option A refers to the Aufbau principle, option C refers to the maximum number of electrons in an orbital based on the formula 2n^2, and option D refers to Coulomb's law, which describes the electrostatic force between charged particles.