1. The layer of the skin responsible for new skin cell production is the:

A. Stratum corneum
B. Stratum basale
C. Stratum granulosum
D. Stratum spinosum

Correct answer: B

Rationale: The correct answer is B: Stratum basale. The stratum basale, also known as the basal layer or stratum germinativum, is the deepest layer of the epidermis responsible for new skin cell production through cell division. This layer contains stem cells that continuously divide and differentiate into keratinocytes, which eventually migrate to the outer layers of the epidermis. The stratum corneum (option A) is the outermost layer of the epidermis composed of dead skin cells. The stratum granulosum (option C) is the layer above the stratum basale where keratinocytes undergo changes in their structure. The stratum spinosum (option D) is a layer above the stratum basale where cells become interconnected by desmosomes. Therefore, the stratum basale is the primary layer responsible for the production of new skin cells.

2. Which term describes the functional unit of a skeletal muscle responsible for muscle contraction?

A. Myofibril
B. Sarcomere
C. Tendon
D. Myoglobin

Correct answer: b

Rationale: The correct answer is B: Sarcomere. A sarcomere is the functional unit of a skeletal muscle responsible for muscle contraction. It is made up of overlapping filaments of actin and myosin proteins. Myofibrils are long, cylindrical structures within muscle cells that contain sarcomeres. Tendons are tough bands of fibrous connective tissue that connect muscles to bones and facilitate movement. Myoglobin is a protein found in muscle cells that stores oxygen for muscle use during exercise. Therefore, the sarcomere is specifically responsible for muscle contraction, making it the correct answer in this question.

3. What is the process by which the body maintains a relatively constant blood pH level, even with changes in blood carbon dioxide concentration?

A. Cellular respiration
B. Gas exchange
C. Buffering system
D. Deoxygenation

Correct answer: C

Rationale: The correct answer is C: Buffering system. The body maintains a relatively constant blood pH level through the buffering system, which consists of chemical substances that can absorb excess hydrogen ions or release hydrogen ions to adjust pH levels. This system helps prevent drastic changes in blood pH even when there are fluctuations in blood carbon dioxide concentration. Cellular respiration and gas exchange are processes related to obtaining and utilizing oxygen, while deoxygenation refers to the removal of oxygen from a substance. Therefore, the buffering system is specifically responsible for regulating blood pH levels in response to changes in carbon dioxide concentration.

4. Polymers are

A. Large molecules formed by repeating units called monomers
B. Simple organic molecules with low boiling points
C. Highly reactive compounds used in industrial processes
D. Insoluble solids with no definite structure

Correct answer: A

Rationale: The correct answer is A: 'Large molecules formed by repeating units called monomers.' Polymers are macromolecules made up of repeating units called monomers, which are linked together through chemical bonds. This repetition results in long chains or networks of molecules, giving polymers their unique properties. Options B, C, and D are incorrect because polymers are not simple organic molecules with low boiling points, highly reactive compounds used in industrial processes, or insoluble solids with no definite structure. Understanding the basic definition of polymers helps us appreciate their wide range of applications in materials science, engineering, and everyday products.

5. An IV drip delivers 40 drops per minute, each containing 1mg of medication. How many milligrams are administered in 3 hours (180 minutes)?

A. 360mg
B. 720mg
C. 7,200mg
D. 14,400mg

Correct answer: C

Rationale: Rationale: In this scenario, we first calculated the total number of drops administered in 3 hours by multiplying the drops per minute by the total number of minutes. Then, we converted the drops to milligrams by multiplying the total drops by the amount of medication in each drop. This method ensures an accurate calculation of the total amount of medication administered over the given time period.