1. Which digestive enzyme is primarily responsible for breaking down proteins?

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

Correct answer: A

Rationale: The correct answer is A: Pepsin. Pepsin is primarily responsible for breaking down proteins in the stomach. It is an enzyme produced by the gastric chief cells in the stomach lining and works in a highly acidic environment to break down proteins into smaller peptide fragments. Lipase, on the other hand, is responsible for breaking down fats, amylase for breaking down carbohydrates, and maltase for breaking down maltose (a type of sugar). Therefore, pepsin is the correct enzyme involved in the digestion of proteins.

2. The two main divisions of the skeletal system are:

A. Upper and lower body bones
B. Axial and appendicular skeleton
C. Long and short bones
D. Compact and spongy bone

Correct answer: B

Rationale: The correct answer is B: Axial and appendicular skeleton. The skeletal system is divided into two main parts: the axial skeleton, which includes the skull, rib cage, and vertebral column, and the appendicular skeleton, which includes the bones of the arms, legs, shoulders, and hips. This division is based on the location and function of the bones in the body. The other options are incorrect as they do not represent the main divisions of the skeletal system. Understanding these divisions is important for studying the structure and function of the human skeletal system.

3. Which sentence uses the possessive apostrophe correctly?

A. The cats meows filled the room.
B. I visited my friends' house.
C. She borrowed Johns book.
D. The childrens toys were scattered everywhere.

Correct answer: B

Rationale: Option b adds the apostrophe and "s" to show ownership of multiple friends.

4. 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.

5. Stephanie is often seen interacting with the medical intern during coffee breaks and after duty

A. Formal
B. Informal
C. Staff
D. Line

Correct answer: B

Rationale: The correct answer is 'B: Informal.' Stephanie's interactions with the medical intern during coffee breaks and after duty suggest a casual and friendly relationship, rather than a formal or official one. 'Informal' describes interactions that are relaxed, personal, and not bound by strict professional protocols. In contrast, 'formal' interactions would involve more structured and official communication, such as meetings or professional discussions. 'Staff' and 'line' are not relevant in this context, as they do not describe the nature of the relationship between Stephanie and the medical intern.