TEAS Practice Test Science

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: Correct Answer: B (Define the problem) Rationale: 1. Defining the problem is the first step in the scientific method to identify the research focus. 2. It helps in formulating specific research questions and objectives. 3. Before gathering qualitative data, having a clear problem statement is essential to guide the research process. Incorrect Choices: A: Communicating with a scientific journal is not a step in the scientific method, but rather a later stage after conducting research. C: Developing a hypothesis comes after defining the problem to propose a possible explanation for the research question. D: Categorizing data for statistical analysis is done after data collection, not before gathering qualitative data.

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: It runs 3' to 5'. The antisense strand of DNA runs in the opposite direction to the sense strand. This is because DNA strands run antiparallel to each other, with one running 5' to 3' and the other running 3' to 5'. The antisense strand serves as a template for RNA synthesis during transcription, where RNA polymerase reads the antisense DNA strand and synthesizes an RNA molecule that is complementary to it. Choice A is incorrect because the sense strand runs 5' to 3'. Choice C is incorrect because the antisense strand is not directly involved in replication; it is mainly involved in transcription. Choice D is incorrect because the direction DNA is stored does not depend on the antisense strand.

Correct Answer: C

Rationale: The correct answer is C: Thymus. The thymus is responsible for maturing T cells, a type of white blood cell crucial for immune responses. The thymus is where immature T cells develop into functional T cells through a process called thymic education. The other choices are incorrect because the hypothalamus (A) is involved in regulating hormones, the pineal gland (B) regulates sleep-wake cycles, and the thyroid (D) produces hormones that regulate metabolism. These structures do not have a direct role in maturing T cells.