1. The tiny contractile units within muscle cells are called:

A. Myocytes
B. Myofibrils
C. Sarcomeres
D. Tendons

Correct answer: C

Rationale: The correct answer is C: Sarcomeres. Sarcomeres are the basic contractile units within muscle cells. They are made up of overlapping filaments of actin and myosin proteins, which slide past each other during muscle contraction, resulting in muscle movement. Myocytes (A) are muscle cells, myofibrils (B) are cylindrical structures within muscle fibers composed of sarcomeres, and tendons (D) are tough bands of connective tissue that connect muscle to bone. Therefore, sarcomeres are specifically responsible for muscle contraction within muscle cells.

2. Which statement accurately defines power?

A. Power is the amount of energy stored in an object
B. Power is the rate at which energy is transferred or work is done
C. Power is the maximum force exerted by an object
D. Power is the resistance of an object to change in motion

Correct answer: b

Rationale: Power measures how quickly work is done or energy is transferred or converted.

3. What figure of speech is used in the statement "His words were a dagger to my heart"?

A. Metonymy
B. Simile
C. Metaphor (Correct)
D. Hyperbole

Correct answer: C

Rationale: The statement compares the pain of his words to a physical object, forming a metaphor.

4. Positron emission tomography (PET) scans utilize a key property of positrons for medical imaging. What is this property?

A. High mass
B. Positive charge
C. Extreme stability
D. Identical behavior to electrons

Correct answer: B

Rationale: The correct answer is B: 'Positive charge.' Positron emission tomography (PET) scans rely on the fact that positrons are positively charged particles. When a positron is emitted during radioactive decay, it quickly collides with an electron, resulting in annihilation and the release of two gamma rays in opposite directions. These gamma rays are detected by the PET scanner to create detailed images of the body's internal organs and tissues. The positive charge of positrons is crucial for this process to occur, making option B the correct choice.

5. Identify the incorrect usage of punctuation in the following sentence: "The children, eager to play, ran outside. It was a beautiful day."

A. comma after "children"
B. comma after "play"
C. period after "outside"
D. no errors

Correct answer: C

Rationale: The two sentences are independent clauses and should be separated by a semicolon or period, not a comma.

6. What is the waste product of protein digestion?

A. Glucose
B. Amino acids
C. Fatty acids
D. Ammonia

Correct answer: D

Rationale: Rationale: Protein digestion involves breaking down proteins into their constituent amino acids. During this process, the waste product produced is ammonia. Ammonia is a toxic compound that needs to be converted into urea in the liver and then excreted by the kidneys in the form of urine. Glucose is a product of carbohydrate digestion, amino acids are the building blocks of proteins, and fatty acids are the end products of fat digestion.