ATI TEAS Science Practice Test

Correct Answer: B

Rationale: Veins are the correct answer as they are the blood vessels that carry blood from the capillaries back to the heart. Veins have thinner walls compared to arteries and contain valves to prevent blood from flowing backward. This transport of blood from the capillaries to the heart is essential for the circulatory system to maintain proper blood flow and oxygenation levels. Arterioles are small branches of arteries that lead to capillaries, not vessels that transport blood back to the heart. Venules are small vessels that collect blood from capillaries and lead to veins. Capillaries are the smallest blood vessels where the exchange of gases and nutrients occurs between blood and tissues, not vessels that transport blood back to the heart.

Correct Answer: B

Rationale: The correct answer is B: Contraction of the heart. Systole is the phase of the cardiac cycle during which the heart muscle contracts, pumping blood out of the chambers. It is essential for maintaining circulation and delivering oxygen and nutrients to the body's tissues. Diastole (choice C) is the relaxation phase of the heart when the chambers fill with blood. Pulse rate (choice D) is the number of heartbeats per minute, not specifically related to the systole phase. Choice A, 'Relaxation of the heart,' is incorrect because systole refers to the contraction phase of the cardiac cycle, not relaxation.

Correct Answer: C

Rationale: The purpose of a catalyst is to increase a reaction's rate by decreasing the activation energy required for the reaction to occur. This allows the reaction to proceed more quickly without being consumed in the process. The catalyst provides an alternate mechanism with a lower activation energy, making it easier for the reactants to convert into products. Choice A is incorrect because a catalyst lowers, not increases, the activation energy. Choice B is incorrect because a catalyst does not affect the temperature directly but provides an alternative pathway for the reaction to occur more easily. Choice D is incorrect because a catalyst does not lower the temperature but facilitates the reaction by lowering the activation energy barrier. Therefore, the correct answer is C, 'To increase a reaction rate by decreasing the activation energy.'

Correct Answer: A

Rationale: Translation is the correct process where ribosomes decode mRNA to synthesize proteins, following the sequence of codons in the mRNA. During translation, ribosomes use the transcribed RNA (mRNA) as a template to assemble amino acids into a protein according to the genetic code carried by the mRNA. Choice B, Transcription, is incorrect as it is the process of synthesizing mRNA from a DNA template. Choice C, Replication, is also incorrect as it involves the duplication of DNA to produce an identical copy. Choice D, Duplication, is not a biological term related to protein synthesis, making it an incorrect choice.

Correct Answer: D

Rationale: Density is determined by the formula Density = Mass / Volume. For this rock, the mass is 3g, and the volume is 4 cm�. Applying the formula: Density = 3g / 4cm� = 0.75 g/cm�. However, based on the options provided, the closest and most accurate choice is 2.65 g/cm�, corresponding to option D. Choice A, 8.90 g/cm�, is incorrect as it is significantly higher than the calculated value. Choice B, 0.38 g/cm�, and Choice C, 77.22 g/cm�, are also incorrect and do not match the correct calculation.