1. The WBC (white blood cell) type responsible for the initial attack on pathogens is:

A. Red blood cells
B. Platelets
C. Phagocytes
D. Lymphocytes

Correct answer: C

Rationale: The correct answer is C: Phagocytes. Phagocytes are a type of white blood cell that plays a crucial role in the immune response by engulfing and destroying pathogens. They are the first line of defense against invading microorganisms, initiating the initial attack on pathogens. Red blood cells (option A) are responsible for carrying oxygen, not for immune responses. Platelets (option B) are involved in blood clotting. Lymphocytes (option D) are another type of white blood cell but are mainly responsible for specific immune responses rather than the initial attack on pathogens.

2. A medication order is written as 3/4 of a tablet. If each tablet is 500mg, what is the equivalent dosage in milligrams?

A. 375mg
B. 425mg
C. 450mg
D. 475mg

Correct answer: A

Rationale: Multiply the tablet strength (500mg) by the fractional dose (3/4) to get 375 milligrams.

3. Which phenomenon describes the bending of light as it travels from one medium to another with differing densities?

A. Reflection
B. Refraction
C. Diffraction
D. Dispersion

Correct answer: B

Rationale: The correct answer is B: Refraction. Refraction is the phenomenon that describes the bending of light as it travels from one medium to another with differing densities. When light passes from one medium to another, such as from air to water, its speed changes, causing it to bend. This bending of light is what we observe when a pencil appears bent in a glass of water. Reflection, on the other hand, is the bouncing back of light when it hits a surface. Diffraction refers to the bending of light around obstacles, and dispersion is the separation of light into its different colors. Therefore, in this case, refraction is the most appropriate term to describe the bending of light as it moves between media with different densities.

4. Which of the following best describes a chemical change?

A. Melting ice to form water
B. Dissolving sugar in water
C. Burning wood to produce ash
D. Crushing a can to reduce its size

Correct answer: c

Rationale: Chemical changes involve the formation of new substances with different chemical properties. Burning wood involves a chemical reaction where wood undergoes combustion, breaking down its chemical structure to produce new substances like ash and gases.

5. What is the process of breaking down glucose into pyruvate called?

A. Glycolysis
B. Gluconeogenesis
C. Krebs cycle
D. Oxidative phosphorylation

Correct answer: A

Rationale: Rationale: A) Glycolysis is the process of breaking down glucose into pyruvate. This occurs in the cytoplasm of cells and is the first step in cellular respiration. B) Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources, such as amino acids or glycerol, and is the opposite of glycolysis. C) The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria and is involved in the oxidation of acetyl-CoA to produce ATP and other energy carriers. D) Oxidative phosphorylation is the final stage of cellular respiration where ATP is produced through the transfer of electrons in the electron transport chain.

6. The main function of the nephrons is to:

A. Store urine
B. Filter blood and remove waste products
C. Produce hormones
D. Control blood pressure

Correct answer: B

Rationale: The correct answer is B: 'Filter blood and remove waste products.' Nephrons are the functional units of the kidneys responsible for filtering blood to remove waste products, excess ions, and water, while reabsorbing essential substances like glucose and amino acids. This process forms urine, which is stored in the bladder before being excreted. Options A, C, and D are incorrect because nephrons do not store urine, produce hormones, or directly control blood pressure; although the kidneys do play a role in long-term blood pressure regulation through mechanisms like the renin-angiotensin-aldosterone system.