1. Which molecule allows for the selective passage of materials into and out of the cell?

A. DNA
B. Protein
C. Carbohydrate
D. Phospholipid bilayer

Correct answer: D

Rationale: The correct answer is D, the phospholipid bilayer. The phospholipid bilayer is the main component of the cell membrane, which acts as a selective barrier allowing certain molecules to pass through while blocking others. Its structure consists of hydrophilic heads facing outward towards the aqueous environments inside and outside the cell, while the hydrophobic tails face inward creating a semi-permeable barrier. DNA (A) is the genetic material of the cell and is located within the nucleus, not involved in material passage. Proteins (B) and carbohydrates (C) are important components of the cell membrane and play various roles, but they do not directly control the selective passage of materials in and out of the cell.

2. A bottle of hand sanitizer contains 70% alcohol. If 5ml of sanitizer are used, how much pure alcohol is present?

A. 1.4ml
B. 2.1ml
C. 2.8ml
D. 3.5ml

Correct answer: D

Rationale: Multiply the total sanitizer volume (5ml) by the alcohol percentage (70%) to get 3.5ml of pure alcohol.

3. What is the formula to calculate kinetic energy?

A. Kinetic Energy = Mass Ã— Velocity
B. Kinetic Energy = Force Ã— Distance
C. Kinetic Energy = Power Ã— Time
D. Kinetic Energy = Potential Energy Ã· Time

Correct answer: a

Rationale: Kinetic energy is calculated using the formula KE = Â½ Ã— mass Ã— velocityÂ².

4. What is an example of a fibrous protein?

A. Insulin
B. Keratin
C. Hemoglobin
D. Collagen

Correct answer: D

Rationale: Rationale: A) Insulin is a hormone, not a fibrous protein. Insulin is produced in the pancreas and is involved in regulating blood sugar levels. B) Keratin is a fibrous structural protein found in hair, nails, and the outer layer of skin. It provides strength and protection. C) Hemoglobin is a globular protein found in red blood cells that is responsible for carrying oxygen from the lungs to the rest of the body. It is not a fibrous protein. D) Collagen is a fibrous protein that is the main component of connective tissues such as tendons, ligaments, and skin. It provides strength and structure to these tissues.

5. What property of a wave is measured in Hertz (Hz)?

A. Amplitude
B. Wavelength
C. Speed
D. Frequency

Correct answer: d

Rationale: Frequency, the number of oscillations per second, is measured in Hertz (Hz).

6. What is the law of conservation of energy?

A. Energy cannot be created, only destroyed
B. Energy can be created but not destroyed
C. Energy can neither be created nor destroyed, only transformed from one form to another
D. Energy is always created in any process

Correct answer:

Rationale: According to the law of conservation of energy, the total energy in a closed system remains constant; it can change forms but cannot be created or destroyed.