Science TEAS Practice Test

Correct Answer: B

Rationale: The correct answer is B: Thymine. Thymine is a nucleobase that exists in DNA, not RNA. RNA contains Uracil instead of Thymine. This is due to a different chemical structure in RNA which lacks the methyl group present in Thymine. Uracil pairs with Adenine in RNA, while Thymine pairs with Adenine in DNA. Choices A, C, and D (Uracil, Cytosine, Guanine) are all nucleobases found in RNA, making them incorrect answers.

Correct Answer: B

Rationale: The correct answer is B: A model. A model is a representation of a natural pattern or occurrence that simplifies complex systems to make them easier to understand and study. Models can simulate natural phenomena that are difficult or impossible to experience directly, allowing scientists to make predictions and test hypotheses. The other choices are incorrect because: A: A theory is an explanation based on evidence and reasoning, not necessarily something difficult to experience directly. C: A law describes a recurring phenomenon but may not involve a representation or simulation of the phenomenon. D: An observation is a direct act of seeing or noting something, not a representation of a complex natural pattern.

Correct Answer: A

Rationale: The correct answer is A: Phenotype. Phenotype refers to the physical and visible expression of a genetic trait. It includes observable characteristics like eye color, height, and hair texture. This is different from genotype, which represents the genetic makeup of an organism. Allele refers to different forms of a gene, and gamete is a reproductive cell. Thus, in this context, phenotype best describes the physical manifestation of a genetic trait, making it the correct answer.

Correct Answer: C

Rationale: The correct answer is C: Repeat the experiment several more times and apply a statistical analysis to the data. This is the most appropriate next step because it allows the researcher to gather more data to ensure the results are consistent. By repeating the experiment multiple times, the researcher can determine if the observed behavior of the bacteria is reliable and not just due to chance. Additionally, applying statistical analysis will help in drawing meaningful conclusions from the data and identifying any patterns or trends. Choice A is incorrect because it overlooks the contradictory result from the fourth experiment, which is crucial information that should not be ignored in scientific reporting. Choice B is also incorrect as it does not address the need for further investigation to validate the results. Choice D is not the best next step as it introduces a new variable (chemical), which could complicate the analysis and may not directly address the observed behavior of the bacteria in response to the initial chemical.

Correct Answer: D

Rationale: The correct answer is D because the ulna, fibula, and humerus are classified as long bones. Long bones are characterized by their elongated shape, with a shaft and two distinct ends. The ulna and humerus are long bones of the upper extremities, while the fibula is a long bone of the lower extremity. A, the sacrum, is a triangular bone at the base of the spine and is classified as a flat bone. B, the clavicle, is also a flat bone that connects the sternum to the scapula. C, the patella, is a sesamoid bone located in the knee joint and is not classified as a long bone. Therefore, the correct answer is D, as the ulna, fibula, and humerus are examples of long bones based on their structure and function.