TEAS Test 7 science quizlet

Correct Answer: A

Rationale: Melatonin is the hormone produced by the pineal gland that plays a crucial role in regulating sleep-wake cycles and is associated with the body's internal circadian rhythm. Melatonin levels typically rise in the evening, signaling to the body that it is time to sleep, and decrease in the morning, helping to wake up and feel alert. Serotonin, dopamine, and endorphins are neurotransmitters that serve different functions in the body and are not primarily responsible for regulating sleep-wake cycles. Serotonin is involved in regulating mood, appetite, and sleep. Dopamine plays a role in reward-motivated behavior and motor control. Endorphins are involved in pain regulation and are often referred to as the body's natural painkillers.

Correct Answer: C

Rationale: Fluorescent microscopy relies on the property of certain molecules to fluoresce when exposed to specific wavelengths of light. When these molecules absorb light energy, they become excited and then emit light at a longer wavelength, producing a visible image. This emitted light is what is used to create the image in fluorescent microscopy, making option C, fluorescence emission, the correct answer. Staining properties (option A) are used to enhance contrast in microscopy but are not the primary mechanism in fluorescent microscopy. Light absorption (option B) is involved in the excitation of fluorescent molecules but is not the property used to create the visible image. Refraction (option D) is the bending of light as it passes through different mediums and is not the property utilized in fluorescent microscopy.

Correct Answer: C

Rationale: The simple columnar epithelium lining the small intestine is crucial for absorption. This type of epithelium is specialized for absorption due to its tall and closely packed cells, which increase the surface area available for nutrient absorption. The primary function of the small intestine is to absorb nutrients from digested food, and the simple columnar epithelium's structure aids in this process by providing a large surface area for absorption. Choices A, B, and D are incorrect because movement, support, and insulation are not primary functions associated with the simple columnar epithelium in the small intestine. While these functions are essential in other tissues or organs, absorption is the key role of the simple columnar epithelium in the small intestine.

Correct Answer: C

Rationale: Lymphocytes, which include B cells, T cells, and natural killer cells, are responsible for coordinating the immune response. They play a crucial role in recognizing and fighting against pathogens and foreign substances in the body. Red blood cells are responsible for oxygen transport, platelets aid in blood clotting, and neutrophils are white blood cells primarily involved in combating infections. Therefore, the correct answer is C, lymphocytes, as they are specifically involved in coordinating immune responses.

Correct Answer: C

Rationale: The correct answer is the uterus. The uterus is a muscular organ in the female body where a developing fetus is nourished and protected during pregnancy. It is the site where a fertilized egg implants and grows into a fetus. The ovaries produce eggs, the fallopian tubes transport the egg to the uterus for potential fertilization, and the vagina serves as the birth canal and the passage for menstrual blood to exit the body. Therefore, the uterus plays a crucial role in pregnancy by providing a nurturing environment for the developing fetus.