1. Which of the following hormones is produced by the adrenal medulla and prepares the body for a stressful situation?

A. Testosterone
B. Cortisol
C. Epinephrine (adrenaline)
D. Growth hormone

Correct answer: C

Rationale: The correct answer is C: Epinephrine (adrenaline). Epinephrine is produced by the adrenal medulla and is responsible for preparing the body for a stressful situation, often referred to as the 'fight or flight' response. Testosterone is a hormone produced by the testes in males and in smaller amounts by the ovaries in females, responsible for male sexual characteristics. Cortisol is produced by the adrenal cortex and plays a role in regulating metabolism and immune response. Growth hormone is produced by the pituitary gland and is essential for growth, cell repair, and metabolism. Therefore, epinephrine is the hormone specifically produced by the adrenal medulla to prepare the body for stress.

2. What is the term for the chemical reaction that involves the loss of electrons?

A. Reduction
B. Oxidation
C. Neutralization
D. Precipitation

Correct answer: b

Rationale: Oxidation is the chemical reaction that involves the loss of electrons. The other choices describe different types of reactions.

3. In a chemical reaction, the total amount of:

A. Matter remains the same
B. Matter increases
C. Matter decreases
D. Energy remains the same

Correct answer: A

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, only rearranged

4. When making a dilution, you...

A. Add more solute to a concentrated solution
B. Change the temperature of the solution
C. Decrease the concentration of a solution
D. All of the above

Correct answer: C

Rationale: The correct answer is C: 'Decrease the concentration of a solution.' When making a dilution, you decrease the concentration of a solution by adding more solvent, not solute. Adding more solute to a concentrated solution would increase the concentration, not dilute it. Changing the temperature of the solution does not directly relate to dilution. Therefore, the only correct statement related to the process of making a dilution is that you decrease the concentration of the solution by adding more solvent, making option C the correct answer.

5. Tight junctions are specialized regions between animal cells that perform which function?

A. Communication between cells
B. Anchorage between cells
C. Selective passage of materials
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Tight junctions are specialized structures between animal cells that serve multiple functions. They facilitate communication between cells by allowing signaling molecules to pass through. Additionally, tight junctions provide anchorage between cells, helping to maintain tissue structure and integrity. Moreover, tight junctions regulate the selective passage of materials across cell layers, acting as a barrier to prevent the free diffusion of substances. Therefore, all the functions mentioned in the options are performed by tight junctions, making 'All of the above' the correct choice.

6. The property of a substance that resists a change in its shape is called:

A. Density
B. Mass
C. Inertia
D. Elasticity

Correct answer: D

Rationale: Elasticity - This refers to a material's ability to resist deformation and return to its original shape after stress is applied. Density, mass, and inertia are related to the substance itself, while viscosity reflects resistance to flow, not shape change.