which organ in the body is responsible for maintaining electrolyte balance and filtering waste from the blood

ATI TEAS 7

ATI TEAS 7 Science

1. Which organ in the body is responsible for maintaining electrolyte balance and filtering waste from the blood?

A. Liver
B. Kidneys
C. Heart
D. Lungs

Correct answer: B

Rationale: The correct answer is B: Kidneys. The kidneys are responsible for filtering waste from the blood and maintaining electrolyte balance. They help regulate the body's fluid levels and produce urine as a means of waste elimination. The liver primarily plays a role in detoxification and metabolism, not in maintaining electrolyte balance or filtering waste from the blood. The heart is responsible for pumping blood, not for electrolyte balance or waste filtration. The lungs are primarily involved in gas exchange, not in maintaining electrolyte balance or filtering waste from the blood.

2. Through which aspect do afferent fibers enter the spinal cord?

A. Through the anterior aspect
B. Through the dorsal aspect
C. Through the ventral aspect
D. Through the lateral aspect

Correct answer: B

Rationale: Afferent fibers, responsible for carrying sensory information, enter the spinal cord through the posterior (dorsal) aspect. Specifically, they enter through the dorsal roots, located on the back (posterior) side of the spinal cord. This route allows sensory information to be transmitted to the central nervous system for processing and integration. Choices A, C, and D are incorrect because afferent fibers do not enter the spinal cord through the anterior, ventral, or lateral aspects.

3. In a covalent bond, the shared electrons:

A. Are completely transferred to one atom.
B. Spend more time closer to the more electronegative atom.
C. Remain equidistant between the two atoms.
D. Do not influence the bond strength.

Correct answer: B

Rationale: In a covalent bond, the shared electrons spend more time closer to the more electronegative atom. Electronegativity is the ability of an atom to attract electrons in a chemical bond. The more electronegative atom exerts a stronger pull on the shared electrons, causing them to be closer to that atom. Choice A is incorrect because in a covalent bond, electrons are shared, not completely transferred. Choice C is incorrect as the shared electrons are not equidistant but are closer to one atom due to electronegativity differences. Choice D is incorrect because shared electrons play a significant role in determining the bond strength by the strength of the bond formed through electron sharing.

4. How do isotopes affect the atomic mass of an element?

A. Isotopes have no effect on the atomic mass of an element.
B. Isotopes cause the atomic mass of an element to vary slightly.
C. Isotopes cause the atomic mass of an element to be exactly the same for all isotopes of that element.
D. Isotopes cause the atomic mass of an element to vary greatly.

Correct answer: B

Rationale: Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Since the atomic mass of an element is the weighted average of the masses of its isotopes, the presence of isotopes causes the atomic mass of an element to vary slightly. This variation occurs because different isotopes have different masses due to their varying numbers of neutrons. The atomic mass is affected by the abundance of each isotope, leading to a slight fluctuation in the overall atomic mass of the element. Choice A is incorrect because isotopes do influence the atomic mass. Choice C is incorrect because isotopes have different masses, affecting the overall atomic mass. Choice D is incorrect as isotopes typically do not cause a significant variation in atomic mass, but rather a slight fluctuation.

5. If Silicon (Si) has an atomic mass of 28.1 AMU (atomic mass units), which of the following is the most likely number of neutrons an atom of Silicon would have?

A. 28.1
B. 14
C. 28
D. 14.2

Correct answer: B

Rationale: Silicon has an atomic number of 14, indicating it has 14 protons. The atomic mass of 28.1 AMU accounts for both protons and neutrons in the nucleus. By subtracting the atomic number from the atomic mass, we can estimate the number of neutrons in the atom. Thus, 28.1 - 14 = 14 neutrons. Choice A is incorrect as it represents the total atomic mass, not the number of neutrons. Choice C is incorrect; it is the atomic number (protons) rather than the number of neutrons. Choice D is incorrect as it is a value that does not reflect the number of neutrons in the silicon atom.