1. What is the term for the process of exchanging gases (oxygen and carbon dioxide) between the blood and the tissues?

A. Inhalation
B. Exhalation
C. External respiration
D. Internal respiration

Correct answer: D

Rationale: The correct answer is D: 'Internal respiration.' Internal respiration refers to the process where oxygen is exchanged for carbon dioxide between the blood and the body tissues at the cellular level. Inhalation (A) and exhalation (B) pertain to the movement of air into and out of the lungs. External respiration (C) involves the exchange of gases between the lungs and the bloodstream. Understanding internal respiration is crucial as it directly impacts the body's ability to supply oxygen to tissues and remove carbon dioxide, which is essential for cellular function and overall health.

2. How does an unbalanced force affect an object at rest?

A. It maintains the object's state of rest
B. It does not affect the object's rest
C. It moves the object into motion
D. It decreases the object's mass

Correct answer: c

Rationale: An unbalanced force acting on an object at rest causes it to start moving.

3. Which type of RNA carries the genetic code from DNA to ribosomes?

A. Ribosomal RNA (rRNA)
B. Transfer RNA (tRNA)
C. Messenger RNA (mRNA)
D. Deoxyribonucleic acid (DNA)

Correct answer: C

Rationale: Rationale: - Messenger RNA (mRNA) carries the genetic information from DNA in the cell's nucleus to the ribosomes in the cytoplasm, where protein synthesis occurs. - Ribosomal RNA (rRNA) is a component of the ribosomes where protein synthesis takes place. - Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosomes during protein synthesis. - Deoxyribonucleic acid (DNA) is the genetic material that contains the instructions for building and maintaining an organism. DNA is transcribed into mRNA before being translated into proteins.

4. What enzyme plays a key role in breaking down carbohydrates in the small intestine?

A. Pepsin
B. Lipase
C. Amylase
D. Trypsin

Correct answer: C

Rationale: Amylase, produced by the pancreas and salivary glands, breaks down carbohydrates into simple sugars like glucose.

5. How many amino acids can make up a protein?

A. 10-20
B. 50-100
C. 100-500
D. 1000+

Correct answer: A

Rationale: Rationale: Proteins are made up of long chains of amino acids. There are 20 standard amino acids that are commonly found in proteins. The sequence and arrangement of these amino acids determine the structure and function of a protein. While proteins can vary in size and complexity, the number of amino acids typically ranges from around 10 to 20 in smaller proteins to hundreds or even thousands in larger proteins. Therefore, the range of 10-20 amino acids is the most accurate representation of the number of amino acids that can make up a protein.

6. What is the process by which muscles convert chemical energy (ATP) into mechanical energy (movement)?

A. Photosynthesis
B. Cellular respiration
C. Muscle contraction
D. The sliding filament theory

Correct answer: D

Rationale: The correct answer is D, the sliding filament theory. This theory explains how muscle contraction occurs at a molecular level. During muscle contraction, actin and myosin filaments slide past each other, causing the muscle to shorten and generate movement. This process requires the conversion of chemical energy stored in ATP into mechanical energy to power muscle contractions. Options A and B, photosynthesis and cellular respiration, involve energy production in plants and cells but are not directly related to muscle movement. Option C, muscle contraction, is a broad term that encompasses the entire process of muscle movement, while option D specifically addresses the molecular mechanism behind muscle contraction.