TEAS Practice Test Science

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: B

Rationale: Sure, here's the step-by-step rationale for why choice B is the correct answer: 1. Qualitative research is subjective. 2. Scientific arguments should rely on objective, quantitative data. 3. Extensive use of qualitative research weakens objectivity. 4. Objective data strengthens scientific arguments. Summary of other choices: A: Lack of bias strengthens a scientific argument by ensuring objectivity. C: Reproducibility strengthens a scientific argument by validating results. D: Standing the test of time strengthens a scientific argument by showing consistency.

Correct Answer: B

Rationale: The large intestine's main role is to absorb water and form feces. First, undigested material passes from the small intestine to the large intestine. Second, water is absorbed, making the stool more solid. Finally, the formed feces are stored until they are eliminated from the body. This process is crucial for maintaining proper hydration and eliminating waste. Choices A, C, and D are incorrect as they describe functions performed by other parts of the digestive system, such as the stomach and small intestine.

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.