1. Urinary system health can be maintained through various lifestyle practices. Which of the following is NOT recommended for optimal urinary system health?

A. Limiting high-sodium foods in the diet
B. Consuming adequate amounts of cranberry juice
C. Holding urine in the bladder for long periods
D. Getting regular moderate-intensity exercise

Correct answer: C

Rationale: The correct answer is C: Holding urine in the bladder for long periods. This is not recommended for optimal urinary system health because it can increase the risk of urinary tract infections and bladder problems. It is important to empty the bladder regularly to prevent bacteria from multiplying and causing infections. Limiting high-sodium foods in the diet helps maintain kidney health by reducing the risk of kidney stones and high blood pressure. Consuming cranberry juice can help prevent urinary tract infections due to its antibacterial properties. Regular moderate-intensity exercise promotes overall health, including good circulation to the kidneys and bladder.

2. Which sentence uses the modal verb "should" correctly?

A. You should have studied harder for the exam.
B. I should be going now.
C. She said she should have taken a different route.
D. They should be arriving any minute now.

Correct answer: B

Rationale: Option B conveys an intention or expectation regarding the present or near future.

3. 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.

4. What are the building blocks of proteins?

A. Sugars
B. Fatty acids
C. Amino acids
D. Nucleotides

Correct answer: C

Rationale: Rationale: Proteins are macromolecules made up of long chains of amino acids. Amino acids are the building blocks of proteins and are linked together through peptide bonds to form polypeptide chains, which then fold into specific three-dimensional structures to carry out various functions in the body. Sugars (A) are the building blocks of carbohydrates, fatty acids (B) are the building blocks of lipids, and nucleotides (D) are the building blocks of nucleic acids like DNA and RNA.

5. Which of the following is an example of a decomposition reaction?

A. 2H2 + O2 â†’ 2H2O
B. CaCO3 â†’ CaO + CO2
C. 2Na + Cl2 â†’ 2NaCl
D. N2 + 3H2 â†’ 2NH3

Correct answer: b

Rationale: Decomposition reactions involve the breakdown of a compound into simpler substances.

6. Which hormone, produced by the pineal gland, plays a role in regulating sleep-wake cycles and is often associated with the body's internal circadian rhythm?

A. Melatonin
B. Serotonin
C. Dopamine
D. Endorphin

Correct answer: a

Rationale: The correct answer is A: Melatonin. Melatonin is a hormone produced by the pineal gland that plays a crucial role in regulating sleep-wake cycles and is closely tied to the body's circadian rhythm. It is often referred to as the 'sleep hormone' because it helps signal to the body when it is time to sleep and wake up. Serotonin (option B) is a neurotransmitter that plays a role in mood regulation and happiness. Dopamine (option C) is involved in reward-motivated behavior and movement. Endorphins (option D) are neuropeptides that act as natural painkillers and contribute to feelings of pleasure. Therefore, Melatonin is the hormone associated with the body's internal circadian rhythm and sleep-wake cycles.