ATI TEAS 7 Science

Correct Answer: B

Rationale: The correct answer is B: 23. In humans, each normal cell contains 23 pairs of chromosomes, making a total of 46 chromosomes. The pairs consist of one chromosome from each parent, ensuring genetic diversity. Choices A, C, and D are incorrect because they do not reflect the accurate number of chromosome pairs in a human cell. Option A (46) is the total number of chromosomes, not pairs. Option C (64) and D (32) are not the correct numbers of chromosome pairs in a human cell.

Correct Answer: A

Rationale: The correct answer is A: Pulmonary vein. The pulmonary vein is the only blood vessel among the choices that carries oxygenated blood from the lungs back to the heart. The pulmonary artery (B) carries deoxygenated blood from the heart to the lungs. The aorta (C) carries oxygenated blood from the heart to the rest of the body. The vena cava (D) carries deoxygenated blood from the body back to the heart. Therefore, the pulmonary vein is the only blood vessel in the list that fits the description of carrying oxygenated blood from the lungs to the heart.

Correct Answer: B

Rationale: The correct answer is B because it demonstrates a single displacement reaction where zinc (Zn) displaces hydrogen (H) in hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2). This is evident from the activity series where Zn is more reactive than H. A, C, and D are not examples of single displacement reactions. A represents a synthesis reaction where hydrogen and oxygen combine to form water. C represents a decomposition reaction where calcium carbonate breaks down into calcium oxide and carbon dioxide. D represents a combustion reaction where methane reacts with oxygen to form carbon dioxide and water.

Correct Answer: B

Rationale: The correct answer is B: Lactic acid. When creatine phosphate is used as an energy source for short bursts of muscle activity, it is rapidly broken down into creatine and phosphate. The breakdown of creatine phosphate leads to the production of lactic acid through anaerobic glycolysis. Lactic acid accumulation causes muscle fatigue during intense exercise. A: Glucose is not the breakdown product of creatine phosphate. Glucose is a common fuel for cellular respiration but is not directly produced from creatine phosphate breakdown. C: Carbon dioxide is not the breakdown product of creatine phosphate. Carbon dioxide is produced during the Krebs cycle in aerobic respiration, not from the breakdown of creatine phosphate. D: Creatine is not the breakdown product of creatine phosphate. Creatine is one of the compounds formed when creatine phosphate is broken down, but it is not the final breakdown product.

Correct Answer: B

Rationale: The correct answer is B: Refraction. Refraction occurs when light bends as it passes through different mediums of varying densities, such as hot air above a desert surface. This bending of light causes the mirage effect where distant objects appear distorted or displaced. Diffraction (A) is the bending of light around obstacles, not relevant in this context. Interference (C) involves the interaction of light waves, not applicable to mirages. Polarization (D) is the orientation of light waves, unrelated to the mirage effect in deserts.