ATI TEAS 7 Science

Correct Answer: B

Rationale: The correct answer is B: Kidneys. The kidneys are responsible for maintaining electrolyte balance through processes like reabsorption and excretion. They also filter waste from the blood to form urine. The liver primarily processes nutrients and detoxifies substances. The heart is responsible for pumping blood, not filtering waste. The lungs are involved in gas exchange, not electrolyte balance or waste filtration. Therefore, the kidneys are the correct choice for this function.

Correct Answer: B

Rationale: The correct answer is B: Glomerulus. The glomerulus is a tuft of capillaries located within the nephron, specifically in the renal cortex. It is responsible for filtering blood and forming the initial filtrate in the process of urine formation. The other choices are incorrect because: A: Ureter - a tube that carries urine from the kidneys to the bladder. C: Nephron - the functional unit of the kidney that includes the glomerulus but is not solely responsible for filtering blood. D: Renal artery - carries oxygenated blood to the kidneys but is not directly involved in the filtration process.

Correct Answer: A

Rationale: The correct answer is A: Nucleosome. Nucleosomes are the basic units of DNA packaging in eukaryotic cells, consisting of DNA wrapped around histone proteins. This structure helps in compacting the DNA to fit inside the nucleus. Choice B (Chromatin) is a broader term for DNA and associated proteins, not a specific packaging structure. Choice C (Histone) refers to the protein component of nucleosomes, not the packaging structure itself. Choice D (Centromere) is a region on a chromosome where the kinetochore forms during cell division, not involved in DNA packaging.

Correct Answer: A

Rationale: Gas exchange takes place in the alveoli, which are tiny air sacs at the end of the bronchioles. Alveoli have a large surface area and thin walls, allowing for efficient exchange of oxygen and carbon dioxide. Bronchioles, bronchi, and trachea are part of the airway passages and are not directly involved in gas exchange. Alveoli are specifically designed for gas exchange due to their structure and proximity to the capillaries.

Correct Answer: B

Rationale: The correct answer is B: Atom. An atom is the smallest unit of matter that retains the properties of an element. Atoms are made up of protons, neutrons, and electrons. A molecule (A) consists of two or more atoms bonded together. A compound (C) is a substance composed of two or more different elements chemically bonded. An element (D) is a pure substance made up of only one type of atom. Therefore, the smallest unit of matter is the atom.