Science TEAS Practice Test

Correct Answer: D

Rationale: The correct answer is D because all the statements provide reasonable explanations for the decrease in mortality during childbirth in the 21st century. A: Cesarean sections can be life-saving in cases of complications like prolonged labor or fetal distress. B: Monitoring tools help detect issues early, allowing for timely interventions and prevention of complications. C: Good hand hygiene reduces the risk of infections that could lead to maternal mortality. Therefore, by combining the advancements in cesarean sections, monitoring tools, and infection prevention practices, modern healthcare has significantly reduced maternal mortality rates compared to the 18th century.

Correct Answer: C

Rationale: The correct answer is C: Circulatory system. This system, composed of the heart, blood vessels, and blood, is responsible for transporting nutrients, gases, and wastes throughout the body. The heart pumps blood carrying oxygen and nutrients to cells and removes waste products. The blood vessels distribute these substances to tissues and organs. The respiratory system (A) is responsible for gas exchange but not for transporting nutrients and wastes. The digestive system (B) processes food and absorbs nutrients but does not transport gases. The nervous system (D) coordinates body functions and transmits signals but does not transport nutrients, gases, or wastes.

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.

Correct Answer: D

Rationale: The correct answer is D because the immune system is responsible for protecting the body from infections by identifying and eliminating harmful pathogens. It helps the body recognize and respond to foreign invaders such as bacteria and viruses. The hypothalamus (Choice A) is not directly involved in immune system function. While the immune system can help remove toxins, its primary role is to combat infections, not filter toxins from the blood (Choice B). Although infections can sometimes trigger the production of more white blood cells, the immune system's primary function is not to stimulate blood cell production (Choice C).

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.