ati teas 7 science

Correct Answer: B

Rationale: The correct answer is B: 2H2 + O2 → 2H2O. This equation is balanced because there are equal numbers of each type of atom on both sides of the equation. Balancing involves adjusting the coefficients to ensure the conservation of mass. In this case, there are 2 hydrogen atoms on each side and 2 oxygen atoms on each side, making it balanced. Explanation for other choices: A: H2 + O2 → H2O - Not balanced, as there are 2 hydrogen atoms on the left but only 1 on the right. C: 3H2O → 2H2 + O2 - Not balanced, as there are 6 hydrogen atoms on the left but only 2 on the right. D: H2O → H2 + O2 - Not balanced, as there are 1 oxygen atom on the left but 2 on the right.

Correct Answer: C

Rationale: The correct answer is C: Carries specific amino acids to the ribosomes. tRNA is responsible for carrying specific amino acids to the ribosomes during protein synthesis. It recognizes the codons on mRNA and pairs them with the corresponding amino acids. This process ensures that the correct amino acids are added to the growing polypeptide chain. Choice A is incorrect because tRNA does not transcribe DNA into mRNA; that is the role of RNA polymerase. Choice B is incorrect because decoding the genetic code on mRNA is done by tRNA along with the ribosomes. Choice D is incorrect because tRNA does not modify the structure of proteins; that is typically done by enzymes or post-translational modifications.

Correct Answer: B

Rationale: The correct answer is B: Blood pressure. Blood pressure is the term for the pressure exerted by blood against the walls of blood vessels. It is a crucial indicator of cardiovascular health. Heart rate (A) is the number of times the heart beats per minute, not directly related to blood vessel pressure. Cardiac output (C) is the amount of blood pumped by the heart per minute, not the pressure exerted on blood vessel walls. Stroke volume (D) is the volume of blood pumped by the heart in a single contraction, not the pressure against blood vessel walls.

Correct Answer: D

Rationale: The correct answer is D: Volume. Volume refers to the amount of space occupied by an object and is measured in cubic units. It is calculated by multiplying the length, width, and height of an object. Mass (A) is the amount of matter in an object, density (B) is the mass per unit volume, and weight (C) is the force of gravity acting on an object. Therefore, Volume is the only property that directly relates to the amount of space occupied by an object, making it the correct answer.

Correct Answer: A

Rationale: The correct answer is A: Atom. An atom is the smallest unit of an element that retains its chemical properties. Atoms are composed of protons, neutrons, and electrons. Molecules (B) are made up of two or more atoms bonded together. Compounds (C) are substances composed of two or more different elements chemically bonded. Mixtures (D) are combinations of two or more substances that are physically mixed but not chemically bonded. Therefore, in this context, the correct answer is atom as it specifically refers to the smallest amount of an element that can exist independently with its unique chemical properties.