1. What is the protective fluid that surrounds the brain and spinal cord?

A. Blood
B. Cerebrospinal fluid
C. Myelin sheath
D. Insulin

Correct answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. This fluid acts as a cushion for the brain and spinal cord, providing protection from impacts. Blood is essential for transporting nutrients and oxygen, but it does not directly surround or protect these vital nervous system structures. Myelin sheath is a fatty substance that insulates nerve fibers, not the fluid surrounding the nervous system. Insulin is a hormone involved in regulating blood sugar levels and is not related to protecting the brain and spinal cord.

2. 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.

3. Which hormone, produced by the adrenal glands, helps regulate the body's response to stress, including increasing blood pressure and suppressing the immune system?

A. Aldosterone
B. Epinephrine
C. Cortisol
D. Insulin

Correct answer: c

Rationale: The correct answer is C: Cortisol. Cortisol is a hormone produced by the adrenal glands that plays a crucial role in the body's response to stress. It helps regulate blood pressure by increasing it to prepare the body for stressors. Additionally, cortisol suppresses the immune system to prioritize the stress response. Aldosterone, while also produced by the adrenal glands, primarily regulates electrolyte balance and blood pressure. Epinephrine, produced by the adrenal medulla, is involved in the fight-or-flight response but does not suppress the immune system like cortisol. Insulin, produced by the pancreas, regulates blood sugar levels and is not directly involved in the stress response. Therefore, Cortisol is the hormone that specifically helps regulate the body's response to stress by increasing blood pressure and suppressing the immune system.

4. What is the term for the maximum amount of solute that can dissolve in a solvent at a specific temperature and pressure?

A. Molarity
B. Solubility
C. Concentration
D. Saturation

Correct answer: b

Rationale: Solubility is the maximum amount of solute that can dissolve in a solvent at a specific temperature and pressure. The other choices do not accurately define solubility.

5. What is the building block of DNA?

A. Amino acid
B. Nucleotide
C. Nucleotide
D. Fatty acid

Correct answer: B

Rationale: Rationale: - Amino acids are the building blocks of proteins, not DNA. - Nucleotide is the correct building block of DNA. A nucleotide consists of a sugar (deoxyribose in DNA), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). - The option "C) Nucleotide" is a duplicate of the correct answer "B) Nucleotide." - Fatty acids are not the building blocks of DNA; they are a type of lipid molecule.

6. What are the three main types of RNA?

A. Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)
B. DNA, RNA, and protein
C. Adenine, guanine, cytosine, and thymine
D. Deoxyribose, ribose, and phosphate

Correct answer: A

Rationale: Rationale: - Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis. - Ribosomal RNA (rRNA) is a structural component of ribosomes, which are the cellular machinery responsible for protein synthesis. - Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosome during protein synthesis. Options B, C, and D are incorrect: - Option B lists DNA, RNA, and protein, which are biomolecules but not the three main types of RNA. - Option C lists nitrogenous bases (adenine, guanine, cytosine, and thymine) found in DNA, not types of RNA. - Option D lists components of nucleotides (deoxyribose, ribose, and phosphate), which are building blocks of nucleic