1. 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.

2. How is power related to energy?

A. Power is the same as energy
B. Energy is the rate at which work is done
C. Power is the amount of stored energy
D. Energy is the rate at which power is transferred

Correct answer: b

Rationale: Energy is related to the amount of work done or the capacity to do work, while power measures the rate at which work is done or energy is transferred.

3. Which property of a substance refers to its ability to be stretched into thin wires?

A. Conductivity
B. Viscosity
C. Ductility
D. Malleability

Correct answer: c

Rationale: Ductility refers to a substance's ability to be stretched into thin wires without breaking.

4. A scientist observes a new chemical reaction and proposes a mechanism for how it occurs. What is the BEST way to test this mechanism?

A. Simulate the reaction using computer models.
B. Design experiments to manipulate predicted intermediate steps.
C. Compare the reaction to similar known reactions.
D. Publish the mechanism in a scientific journal.

Correct answer: B

Rationale: Designing experiments to manipulate predicted intermediate steps is the best way to test the proposed mechanism because it directly tests the validity of the proposed mechanism by manipulating the specific steps involved. This approach allows for empirical validation of the proposed mechanism and provides concrete evidence to support or refute it. Simulating the reaction using computer models may provide some insights but does not directly test the mechanism. Comparing the reaction to similar known reactions can provide some context but does not directly test the proposed mechanism. Publishing the mechanism in a scientific journal is important for sharing findings but does not constitute a test of the mechanism itself.

5. Which of the following is NOT a common symptom of pregnancy?

A. Fatigue
B. Nausea
C. Increased urination
D. Loss of appetite

Correct answer: D

Rationale: The correct answer is D: "Loss of appetite." While it is common for pregnant individuals to experience fatigue, nausea, and increased urination due to hormonal changes and the body's adaptations during pregnancy, a loss of appetite is not typically a common symptom. Most pregnant individuals experience increased appetite, particularly in the early stages of pregnancy. This increased appetite is often attributed to the body's need for additional nutrients to support the growing fetus. Therefore, the absence of appetite loss makes option D the correct choice in this question.

6. Fertilization of the egg by sperm typically occurs in the:

A. Ovary
B. Fallopian tube
C. Uterus
D. Vagina

Correct answer: B

Rationale: The correct answer is B: Fallopian tube. Fertilization of the egg by sperm typically occurs in the fallopian tube. After ovulation, the egg travels through the fallopian tube where it can meet sperm for fertilization. The fallopian tube provides an ideal environment for fertilization to occur due to its proximity to the ovaries and the uterus. The other options, A: Ovary, C: Uterus, and D: Vagina, are not the typical sites for fertilization to take place. Therefore, the fallopian tube is the most appropriate location for the union of egg and sperm to form a zygote.