TEAS Practice Test Science

Correct Answer: D

Rationale: The correct answer is D: Vacuole. Vacuoles are responsible for storing food, water, and other materials in the cell. They help maintain turgor pressure and regulate the cell's internal environment. Centrioles are involved in cell division, lysosomes contain digestive enzymes, and ribosomes are responsible for protein synthesis. So, A, B, and C are incorrect choices for food and water storage in the cell.

Correct Answer: D

Rationale: The correct answer is D: Ventilation. Ventilation specifically refers to the mechanical act of breathing, which involves the movement of air in and out of the lungs. This process is essential for the exchange of oxygen and carbon dioxide in the body. A: Diffusion is the process of molecules moving from an area of high concentration to an area of low concentration. While diffusion plays a role in gas exchange during respiration, it is not the mechanical act of breathing itself. B: Perfusion refers to the process of blood flow through the tissues. Although perfusion is vital for delivering oxygen to the body's cells, it is not the mechanical act of breathing. C: Respiration encompasses the entire process of gas exchange in the body, including both ventilation and the exchange of gases at the cellular level. While respiration is closely related to breathing, it is not specifically the mechanical act of breathing.

Correct Answer: A

Rationale: The correct answer is A: Helicase. Helicase is responsible for unwinding the double-stranded DNA during replication by breaking the hydrogen bonds between the base pairs. This allows the DNA strands to separate and serve as templates for the synthesis of new DNA strands by DNA polymerase. Ligase is responsible for joining the DNA fragments together, nuclease is involved in DNA repair by cutting out damaged DNA, and polymerase is responsible for synthesizing new DNA strands based on the template strands. Therefore, only helicase directly unwinds the double-stranded DNA during replication.

Correct Answer: B

Rationale: The correct answer is B: White blood cells. White blood cells, specifically B lymphocytes, are responsible for producing antibodies. B lymphocytes recognize foreign substances (antigens) and produce antibodies to neutralize them. Red blood cells (choice A) are involved in oxygen transport, platelets (choice C) are responsible for blood clotting, and plasma (choice D) is the liquid component of blood that carries nutrients and waste products. Thus, white blood cells are the only cells among the choices directly involved in antibody production.

Correct Answer: C

Rationale: The correct answer is C: Lactic acid and CO2. During anaerobic respiration in humans, glucose is broken down into lactic acid and a small amount of CO2. This process occurs in the absence of oxygen, typically during high-intensity exercise when oxygen supply is limited. Lactic acid buildup causes muscle fatigue. Explanation for why other choices are incorrect: A: Ethyl alcohol and CO2 - This is the byproduct of fermentation in yeast, not human anaerobic respiration. B: Ethyl alcohol only - Ethyl alcohol is not produced during human anaerobic respiration. D: Lactic acid only - While lactic acid is indeed produced during anaerobic respiration in humans, a small amount of CO2 is also generated as a byproduct.