1. What is the breakdown product of ATP (adenosine triphosphate) that provides energy for muscle contraction?

A. Glucose
B. Creatine phosphate
C. ADP (adenosine diphosphate)
D. Lactic acid

Correct answer: C

Rationale: The correct answer is C: ADP (adenosine diphosphate). During muscle contraction, ATP is broken down into ADP and inorganic phosphate, releasing energy that fuels the muscle contraction process. This energy release allows the muscle fibers to contract and perform work. Glucose is a source of energy that is broken down through cellular respiration to produce ATP but is not the direct breakdown product of ATP itself. Creatine phosphate is another energy storage molecule in muscles but is not the breakdown product of ATP. Lactic acid is produced during anaerobic respiration when there is a lack of oxygen, and it is not the primary energy source for muscle contraction. Therefore, ADP is the correct breakdown product of ATP that provides energy for muscle contraction.

2. What is the role of DNA in heredity?

A. Provides energy for the cell
B. Determines the structure and function of proteins
C. Stores and transmits genetic information
D. Controls cell division

Correct answer: C

Rationale: Rationale: DNA (deoxyribonucleic acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It stores genetic information in the form of a code made up of four chemical bases: adenine (A), thymine (T), cytosine (C), and guanine (G). This genetic information is passed down from parents to offspring and is responsible for determining an organism's traits and characteristics. DNA does not provide energy for the cell (option A), determine the structure and function of proteins (option B), or control cell division (option D).

3. Which sentence avoids a comma splice?

A. The wind howled, the branches swayed, and rain lashed against the windows.
B. He packed his bags, he checked the weather forecast, and then hit the road.
C. The movie was entertaining, it was also thought-provoking.
D. Tired and hungry, she stopped for a quick bite at the cafe.

Correct answer: C

Rationale: Option C uses a semicolon to separate two independent clauses, avoiding a comma splice.

4. Which property of a substance refers to its ability to undergo a chemical change and form new substances?

A. Density
B. Mass
C. Reactivity
D. Volume

Correct answer: c

Rationale: Reactivity refers to a substance's ability to undergo chemical changes, forming new substances with different properties.

5. Which of the following is the neutral subatomic particle found in the nucleus of an atom?

A. Electron
B. Proton
C. Neutron
D. Positron

Correct answer: C

Rationale: Neutrons are subatomic particles found in the nucleus of an atom that have no charge. They have a mass of approximately 1 atomic mass unit (amu). The number of neutrons in an atom's nucleus contributes to the mass number of the atom, which is the total number of protons and neutrons in the nucleus.

6. The speed of light in a vacuum is measured in units of:

A. Meters per second
B. Hertz
C. Candela
D. Newton

Correct answer: A

Rationale: The correct answer is A: 'Meters per second.' The speed of light in a vacuum is a fundamental constant of nature and is approximately 299,792,458 meters per second. This speed is constant and does not vary based on the frequency or wavelength of light. Hertz (B) is a unit of frequency, Candela (C) is a unit of luminous intensity, and Newton (D) is a unit of force. Understanding the units used to measure the speed of light is important in physics and related fields to accurately describe the propagation of light in different mediums.