1. The muscular diaphragm plays a vital role in respiration. When it contracts, it:

A. Increases lung volume for inhalation
B. Decreases lung volume for exhalation
C. Filters dust and particles from inhaled air
D. Produces mucus to lubricate the airways

Correct answer: A

Rationale: The diaphragm is a crucial muscle involved in respiration. When the diaphragm contracts, it flattens and moves downwards, increasing the volume in the thoracic cavity. This expansion creates a negative pressure in the lungs, causing air to rush in during inhalation. Therefore, option A, 'Increases lung volume for inhalation,' is the correct answer. The diaphragm's contraction facilitates the breathing process by creating space for the lungs to expand and take in air, making it essential for proper respiration.

2. Which of the following is an example of stabilizing selection?

A. Selection that favors extreme traits in a population
B. Selection that removes individuals with extreme traits
C. Selection that maintains the current average trait in a population
D. Selection that favors one specific trait over all others

Correct answer: C

Rationale: Rationale: - Stabilizing selection is a type of natural selection that favors the intermediate variants in a population, while selecting against the extreme traits. This results in the maintenance of the current average trait in the population. - Option A is incorrect because stabilizing selection does not favor extreme traits; instead, it favors the average trait. - Option B is incorrect because stabilizing selection does not remove individuals with extreme traits; it acts against extreme traits by favoring the intermediate variants. - Option D is incorrect because stabilizing selection does not favor one specific trait over all others; it favors the average trait by selecting against extreme traits.

3. The longest bone in the human body is the:

A. Tibia
B. Fibula
C. Femur
D. Humerus

Correct answer: C

Rationale: The correct answer is C: "Femur." The femur is the longest bone in the human body, located in the thigh region and connecting the hip to the knee. It plays a crucial role in supporting the body's weight and facilitating movement. The tibia and fibula are bones in the lower leg, while the humerus is a bone in the upper arm. Therefore, the femur is the correct answer for the longest bone in the human body.

4. Connective tissue provides support and connects other tissues. What is the main component that gives connective tissue its strength?

A. Collagen fibers
B. Epithelial cells
C. Nerve cells
D. Blood cells

Correct answer: A

Rationale: The main component that gives connective tissue its strength is collagen fibers. Collagen is a fibrous protein that is the most abundant protein in the human body, providing tensile strength and support to tissues. Collagen fibers are arranged in a parallel fashion, giving connective tissue its resilience and ability to withstand stretching forces. Epithelial cells are not the main component of strength in connective tissue; they are specialized cells that line the surfaces of organs and structures. Nerve cells are responsible for transmitting signals and do not contribute to the strength of connective tissue. Blood cells are not structural components of connective tissue but rather play a role in transportation and immune function.

5. Which sentence uses the word "literally" correctly?

A. literally died laughing at that joke.
B. He literally climbed a mountain of paperwork.
C. Her eyes were literally sparkling with excitement.
D. The house was literally haunted by ghosts.

Correct answer: B

Rationale: Option B uses "literally" to emphasize the magnitude of work, not to exaggerate a simple action.

6. Certain medications can suppress the immune system to treat autoimmune diseases or prevent organ rejection after transplants. What is a potential risk associated with immunosuppressive drugs?

A. Increased risk of developing allergies
B. Increased susceptibility to infections
C. Both a and b
D. Neither a nor b

Correct answer: C

Rationale: The correct answer is C: 'Both a and b.' Immunocompromised individuals, who take immunosuppressive drugs, are at an increased risk of developing allergies due to the altered immune response. Additionally, these drugs suppress the immune system's ability to fight off infections, making individuals more susceptible to various pathogens. Therefore, both increased risk of developing allergies and increased susceptibility to infections are potential risks associated with immunosuppressive drugs, making option C the correct choice.