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: C

Rationale: The correct answer is C: Epidermis. The epidermis is the outermost layer of the skin and is avascular, meaning it does not contain blood vessels. This is important for maintaining its protective function and preventing blood loss in case of injury. The hypodermis (A) contains blood vessels that supply the skin with nutrients and regulate temperature. The dermis (B) is rich in blood vessels, providing nourishment to the skin and regulating temperature. Option D (Hyperdermis) is not a recognized layer of the skin, making it an incorrect choice.

Correct Answer: D

Rationale: The correct answer is D: Veins. Veins have the lowest blood pressure among the structures listed. This is because veins have thinner walls and larger lumens compared to arteries and arterioles, which results in less resistance to blood flow and lower pressure. Venules are small vessels that connect capillaries to veins and have slightly higher pressure than veins. Arteries and arterioles have thicker walls and smaller lumens to withstand the higher pressure of blood ejected by the heart. Therefore, veins have the lowest blood pressure due to their structural characteristics.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Meiosis involves two rounds of cell division. 2. In meiosis I, homologous chromosomes separate, resulting in haploid daughter cells with half the number of chromosomes. 3. In meiosis II, sister chromatids separate, resulting in four haploid daughter cells. 4. Since humans have 46 chromosomes in their somatic cells, each resulting cell after meiosis will contain 23 chromosomes. Summary: A: 96 is incorrect as it is a doubled diploid number. B: 54 is incorrect as it is not the correct halving of the diploid human chromosome number. C: 46 is incorrect as it represents the original number of chromosomes in a human somatic cell, not the resulting number after meiosis.

Correct Answer: D

Rationale: The correct answer is D: Homeostasis. The endocrine system is responsible for regulating various physiological processes to maintain internal balance, or homeostasis, within the body. Hormones released by endocrine glands help control metabolism, growth, reproduction, and other functions. Choice A (Heartbeat) is controlled by the cardiovascular system, not the endocrine system. Choice B (Respiration) is controlled by the respiratory system. Choice C (Electrolyte and water balance) is regulated by the kidneys and not directly by the endocrine system. Thus, the primary function of the endocrine system is to maintain homeostasis through hormone regulation.