1. Approximately how many muscles are there in the human body?

A. 100
B. 100
C. 600
D. Over 600

Correct answer: D

Rationale: The correct answer is D. There are over 600 muscles in the human body. Muscles are responsible for movement, posture, and generating heat in the body. The exact number of muscles can vary slightly from person to person, but it is generally accepted that there are over 600 muscles in the human body. These muscles work together to allow us to perform various movements and activities throughout our daily lives.

2. What is the primary factor that determines whether a solute will dissolve in a solvent?

A. Temperature
B. Pressure
C. Molecular structure
D. Particle size

Correct answer: c

Rationale: The molecular structure of the solute and solvent plays a key role in determining solubility. The other choices may influence solubility but are not the primary determining factor.

3. Which energy transformation occurs when a guitar string vibrates to produce sound?

A. Mechanical energy to thermal energy
B. Kinetic energy to potential energy
C. Electrical energy to sound energy
D. Potential energy to kinetic energy

Correct answer: c

Rationale: The electrical energy in the guitar's amplifier is converted into sound energy when the string vibrates.

4. Antigenic variation, a common strategy used by some viruses, allows them to:

A. Produce toxins
B. Evade the immune system
C. Survive outside a host
D. Replicate rapidly

Correct answer: B

Rationale: Rationale: Antigenic variation is a strategy used by some viruses to evade the host's immune response. By constantly changing their surface antigens, viruses can avoid recognition and destruction by the immune system. This allows the virus to persist in the host and continue replicating, leading to prolonged infection and potential transmission to other hosts. Antigenic variation does not directly involve the production of toxins, survival outside a host, or rapid replication, making options A, C, and D incorrect in this context.

5. Imagine you have an element with atomic number 11 and mass number 23. How many neutrons does it have?

A. 11
B. 12
C. 23
D. Cannot be determined without additional information

Correct answer: B

Rationale: Rationale: - The atomic number (Z) of an element is the number of protons in its nucleus. In this case, the element has an atomic number of 11. - The mass number (A) of an element is the sum of its protons and neutrons. Given that the mass number is 23 and the atomic number is 11, we can calculate the number of neutrons by subtracting the atomic number from the mass number: Neutrons = Mass number - Atomic number = 23 - 11 = 12. - Therefore, the element with atomic number 11 and mass number 23 has 12 neutrons.

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.