what happens during expiration

ATI TEAS 7

ATI TEAS Science Practice Test

1. What happens during expiration?

A. The diaphragm contracts and the thoracic cavity expands.
B. The diaphragm relaxes and the thoracic cavity contracts.
C. The thoracic cavity expands, increasing pressure.
D. The diaphragm relaxes and moves upward.

Correct answer: B

Rationale: The correct answer is B. During expiration, the diaphragm relaxes, causing the thoracic cavity to contract. As the thoracic cavity decreases in size, the pressure inside the lungs increases, leading to air flowing out of the lungs. This process helps to expel carbon dioxide-rich air from the body. Choices A, C, and D are incorrect. In choice A, the diaphragm contracting and the thoracic cavity expanding describes inspiration, not expiration. Choice C is incorrect because during expiration, the thoracic cavity actually decreases in size. Choice D is incorrect as the diaphragm moving upward is not a typical movement associated with expiration.

2. What is the difference between exhalation (expiration) and inhalation (inspiration)?

A. Exhalation involves active muscle contraction, while inhalation is passive.
B. Inhalation brings in oxygen-rich air, while exhalation releases carbon dioxide-rich air.
C. Exhalation occurs through the nose only, while inhalation can occur through the nose or mouth.
D. Inhalation warms and humidifies air, while exhalation cools and dries air.

Correct answer: A

Rationale: Exhalation (expiration) involves active muscle contraction, specifically the diaphragm and intercostal muscles, to decrease the volume of the thoracic cavity and push air out of the lungs. In contrast, inhalation (inspiration) is a passive process where the diaphragm and external intercostal muscles contract to increase the thoracic cavity volume, allowing air to flow into the lungs. Choice B is incorrect as exhalation removes carbon dioxide-rich air and inhalation brings in oxygen-rich air. Choice C is incorrect because both exhalation and inhalation can occur through the nose or mouth. Choice D is inaccurate as inhalation humidifies and warms the air, while exhalation cools and dries it.

3. Which factor do colligative properties of solutions depend on?

A. Concentration of the solvent
B. All of the above
C. Chemical identity of the solute
D. Number of solute particles in solution

Correct answer: D

Rationale: Colligative properties of solutions depend on the number of solute particles in solution. These properties, such as boiling point elevation, freezing point depression, vapor pressure lowering, and osmotic pressure, are proportional to the number of solute particles present in the solution. The chemical identity of the solute or the concentration of the solvent does not influence colligative properties, making choices A and C incorrect. Therefore, the correct answer is D, the number of solute particles in solution.

4. What is the scientific term for the study of genes and their role in disease?

A. Molecular biology
B. Biochemistry
C. Evolutionary biology
D. Genomic medicine

Correct answer: D

Rationale: Genomic medicine is the scientific discipline that specifically focuses on the study of genes and their involvement in disease processes. It seeks to understand how variations in an individual's genes can influence their predisposition to certain diseases or affect their response to treatment. This field plays a crucial role in personalized medicine by utilizing genetic information to tailor healthcare decisions and interventions to individual patients. Molecular biology, biochemistry, and evolutionary biology, while related to genetics in various ways, do not have the primary focus on the role of genes in disease as genomic medicine does.

5. What type of reaction is represented by the following equation: 2C₆H₁₄ + 19O₂ → 12CO + 14H₂O?

A. Substitution reaction
B. Acid-base reaction
C. Enzyme reaction
D. Combustion reaction

Correct answer: D

Rationale: The given chemical equation represents a combustion reaction. Combustion reactions involve the burning of a hydrocarbon (C₆H₁₄) in the presence of oxygen (O₂) to produce carbon monoxide (CO) and water (H₂O). Combustion reactions typically release heat and light energy. In this case, the reactants are a hydrocarbon and oxygen, resulting in the formation of carbon monoxide and water. Choices A, B, and C are incorrect because the reaction does not involve substitution, acid-base reactions, or enzyme catalysis. Combustion reactions are characterized by the rapid combination of a substance with oxygen, leading to the production of heat and light energy.