Science TEAS Practice Test

Correct Answer: D

Rationale: Density is considered an intensive property because it remains constant regardless of the amount of the substance present. Intensive properties do not depend on the quantity of the material. Density is defined as mass per unit volume, so it is independent of the amount of the substance. On the other hand, mass and volume (choices A and C) are extensive properties that change with the amount of the substance, making them not intensive. Weight (choice B) is also not an intensive property as it depends on the gravitational force acting on the object, which can vary.

Correct Answer: B

Rationale: To be included in the formation of a scientific conclusion, evidence must be reproducible. This means that the findings can be repeated by other researchers to ensure the validity and reliability of the results. Reproducibility is essential in scientific research to confirm the accuracy of the findings and allow for independent verification. Quantitative evidence, while important in providing numerical data, is not always necessary for forming a scientific conclusion. Qualitative evidence, which describes qualities or characteristics, can also contribute to scientific conclusions. The choice "C: Obvious" is incorrect because scientific evidence may not always be obvious and often requires careful analysis and interpretation. Choice "D: All of the above" is incorrect because not all scientific evidence needs to be quantitative, and while reproducibility is crucial, it is not necessary for evidence to be obvious to be included in forming a scientific conclusion.

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: The sinoatrial node. The SA node is known as the heart's natural pacemaker as it initiates electrical impulses that regulate the heart rate. It is located in the right atrium and generates rhythmic electrical signals that stimulate the cardiac muscle to contract. The left ventricle (B), aorta (C), and tricuspid valve (D) do not serve as electrical stimulators of the cardiac muscle. The left ventricle is a chamber that pumps oxygenated blood, the aorta is the largest artery that carries blood away from the heart, and the tricuspid valve controls blood flow between the right atrium and right ventricle.

Correct Answer: A

Rationale: Step-by-step rationale for answer A: 1. Oxygenated blood from the lungs enters the left atrium. 2. It then passes through the mitral valve into the left ventricle. 3. Upon contraction, it is pumped into the aorta. 4. The oxygenated blood is then dispersed to tissues through a network of arteries and capillaries. Summary of why other choices are incorrect: B: Incorrect because oxygenated blood does not go to the right side of the heart. C: Incorrect because there is no direct connection between the left atrium and the right aorta. D: Incorrect because there is no septal valve and oxygenated blood is not stored in the left ventricle.