ATI TEAS 7
ATI TEAS 7 Version 1 Science Questions
Extract:
Question 1 of 5
Which substance protects the body from ultraviolet rays?
Correct Answer: D
Rationale: Melanin is the pigment responsible for skin color and serves as a natural defense against ultraviolet (UV) rays. When the skin is exposed to UV rays, melanin production increases to absorb and dissipate the radiation, acting as a protective mechanism. This helps prevent DNA damage, reducing the risk of skin cancer and other UV-induced skin issues. Therefore, melanin is the substance that effectively shields the body from the harmful effects of UV radiation.
Extract:
Question 2 of 5
Which of the following synthesizes antidiuretic hormone?
Correct Answer: C
Rationale: The correct answer is C: Hypothalamus. The hypothalamus, located in the brain, synthesizes antidiuretic hormone (ADH), also known as vasopressin. ADH is crucial in regulating water balance by controlling the reabsorption of water in the kidneys. This action reduces urine production, helping to maintain proper fluid levels in the body and prevent dehydration. While the pancreas, thymus, and pineal gland play important roles in the endocrine system, they are not responsible for synthesizing antidiuretic hormone.
Extract:
Question 3 of 5
The breakdown of lactose in the small intestine is mediated by the enzyme lactase, and the products are galactose and glucose. Galactose and glucose are which of the following?
Correct Answer: D
Rationale: Galactose and glucose are both simple sugars consisting of single sugar units. Therefore, they are classified as monosaccharides. This makes option D the correct answer.
Extract:
Question 4 of 5
Which of the following chemicals is released by one type of immune cell to directly activate another immune cell?
Correct Answer: B
Rationale: The correct answer is B: cytokines. Cytokines are signaling molecules released by immune cells to regulate the immune response. They play a crucial role in coordinating and communicating between different immune cells. By releasing cytokines, immune cells can directly activate other immune cells, enhancing the immune response. Lysozymes are enzymes that break down bacterial cell walls, perforin is a protein involved in cell-mediated immune responses, and granzymes are enzymes that induce apoptosis in target cells, mainly used by cytotoxic T cells and natural killer cells, not for directly activating other immune cells.
Question 5 of 5
What is the atomic number of an atom that has 12 protons and 12 neutrons?
Correct Answer: C
Rationale: The atomic number of an element is determined by the number of protons in its nucleus. In this case, the atom has 12 protons, which directly corresponds to its atomic number. Neutrons have no impact on the atomic number; they contribute to the atomic mass. The atomic number uniquely identifies an element based on the number of protons in its nucleus. Therefore, the correct answer is 12, as it represents the number of protons in the nucleus and defines the element, regardless of the presence of neutrons.