ATI TEAS Science Practice Test

Correct Answer: C

Rationale: The correct answer is the mitral valve, also known as the bicuspid valve. The mitral valve prevents blood from flowing back into the left atrium during ventricular contraction. The tricuspid valve is located between the right atrium and right ventricle, the pulmonary valve is between the right ventricle and the pulmonary artery, and the aortic valve is situated between the left ventricle and the aorta. Therefore, choices A, B, and D are incorrect as they are not related to preventing blood from entering the left atrium during ventricular contraction.

Correct Answer: B

Rationale: Oxygenated blood flows from the lungs to the left atrium, then to the left ventricle, and is pumped out through the aorta to the body. This pathway ensures efficient oxygen delivery to the body's tissues and organs. Choice A is incorrect as oxygenated blood does not flow directly from the heart to the brain. Choice C is incorrect as it suggests a route from the body to the right atrium and then to the lungs, which is the pathway for deoxygenated blood. Choice D is incorrect as it describes a direct pathway from the left atrium to the aorta, skipping the left ventricle, which is essential for pumping blood to the body.

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: B

Rationale: The correct answer is B: Skeletal, cardiac, smooth. Skeletal muscle tissue is responsible for voluntary movement, cardiac muscle tissue is found in the heart and is responsible for involuntary heart contractions, and smooth muscle tissue is located in organs and is responsible for involuntary movements. Therefore, the three types of muscle tissues are skeletal, cardiac, and smooth. Choices A, C, and D are incorrect because they include types of tissues that are not classified as muscle tissues. Epithelial and connective tissues are different types of tissues that serve other functions in the body, not related to muscle contractions.

Correct Answer: B

Rationale: Glucagon is a hormone produced in the pancreas and functions to raise blood sugar levels. It does so by signaling the liver to release stored glucose into the bloodstream. Therefore, the correct answer is B, 'Produced in the pancreas, raises blood sugar.' Choices A, C, and D describe functions or locations of other hormones, not glucagon. Glucagon is specifically released by alpha cells in the pancreas, making option B the correct choice.