Science TEAS Practice Test

Correct Answer: A

Rationale: The correct answer is A: The human body has evolved to become more resilient to its environment. This statement is not likely to have contributed to the longer life expectancy in the 21st century. Evolution occurs over long periods of time, not within a span of a few hundred years. Advances in medical technology and treatments (B), higher standards of basic cleanliness (C), and the creation of vaccines (D) have all played significant roles in increasing life expectancy by preventing and treating diseases, improving overall health, and reducing mortality rates. These factors are directly linked to improvements in healthcare and sanitation practices, which have had a tangible impact on life expectancy.

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.

Correct Answer: C

Rationale: The correct answer is C: The rectum. The genitourinary system consists of organs involved in reproduction and waste elimination. The rectum is part of the digestive system, not the genitourinary system. The kidneys (A), urethra (B), and bladder (D) are all essential components directly involved in the production, storage, and elimination of urine. The rectum plays a role in the elimination of solid waste and is not part of the genitourinary system.

Correct Answer: C

Rationale: The correct answer is C: White blood cells. White blood cells, specifically lymphocytes, are responsible for producing antibodies as part of the immune response. Platelets are involved in blood clotting, not antibody production. Red blood cells carry oxygen and do not play a role in immune responses. Plasma cells are a type of white blood cell that produces antibodies, but they are a specialized subset of white blood cells and not the main component responsible for antibody production.

Correct Answer: B

Rationale: To calculate the grams of CaCO3 needed, we first find the molar mass of CaCO3: 40.07 (Ca) + 12.01 (C) + (15.99 x 3) (O) = 100.08 g/mol. Next, use the formula: grams = moles x molar mass. Moles = 0.35 M x 0.6 L = 0.21 moles. Therefore, grams = 0.21 moles x 100.08 g/mol = 21.02 g. Hence, the correct answer is B: 19.7 g. Other choices are incorrect due to miscalculation or incorrect conversion.