1. During inhalation, which muscle contracts to increase the volume of the thoracic cavity, allowing air to flow into the lungs?

A. Diaphragm
B. Intercostal muscles
C. Abdominal muscles
D. Pectoral muscles

Correct answer: A

Rationale: The correct answer is A: Diaphragm. During inhalation, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity. This action creates a pressure difference between the lungs and the atmosphere, causing air to flow into the lungs. The intercostal muscles also play a role by expanding the ribcage, but the primary muscle responsible for increasing thoracic cavity volume during inhalation is the diaphragm. Abdominal muscles are involved in exhalation by contracting to push the diaphragm up, reducing thoracic cavity volume. Pectoral muscles are located in the chest and are not directly involved in the breathing process.

2. What is the functional group present in aldehydes?

A. Hydroxyl
B. Carbonyl
C. Ester
D. Amine

Correct answer: B

Rationale: Aldehydes have the functional group -CHO, which is a carbonyl group bonded to a hydrogen atom. The other choices are associated with different functional groups.

3. Express 0.75 as a fraction.

A. 4/5
B. 3/4
C. 1/2
D. 1/4

Correct answer: B

Rationale: Decimals can be represented as fractions where the denominator is a power of 10 (in this case, 10 raised to the power of -1, or 1/10th). So, 0.75 is equivalent to 7/10. We can simplify this fraction by dividing the numerator and denominator by 5, resulting in 3/4.

4. A new medication claims to reduce allergy symptoms by 90%. A study is conducted where 100 participants with allergies take the medication, and 90 report symptom reduction. Should this be enough evidence to recommend the medication for everyone?

A. Yes, the study shows clear effectiveness.
B. No, the sample size is too small.
C. No, a control group without the medication is needed.
D. No, long-term effects haven't been studied.

Correct answer: C

Rationale: : Comparing the medication group to a group receiving a placebo (inactive substance) would help isolate the medication's true effect and avoid attributing symptom reduction to other factors.

5. What is the process of transporting molecules across the cell membrane against a concentration gradient called?

A. Diffusion
B. Osmosis
C. Active transport
D. Facilitated diffusion

Correct answer: C

Rationale: Rationale: A) Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, which does not require energy input. B) Osmosis is the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration. C) Active transport is the process of transporting molecules across the cell membrane against a concentration gradient, requiring energy in the form of ATP to move substances from an area of lower concentration to an area of higher concentration. D) Facilitated diffusion is a type of passive transport that involves the use of transport proteins to move molecules across the cell membrane from an area of higher concentration to an area of lower concentration, without the need for energy input.