ati teas 7 science

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: D

Rationale: Step 1: Given the object is moving in a circle at a constant speed, it experiences centripetal acceleration towards the center. Step 2: According to Newton's first law, an object in motion stays in motion unless acted upon by a net force. Step 3: The only force causing the object to change its direction is the centripetal force. Step 4: Therefore, the net force acting on the object is required to continuously change its direction. Summary: Choice A is incorrect because the net force is not always present. Choice B is incorrect as centripetal force acts on the object. Choice C is incorrect as speed can be constant in circular motion.

Correct Answer: B

Rationale: The primary function of the small intestine is to absorb nutrients from digested food. This process involves breaking down food into smaller molecules that can be absorbed into the bloodstream for energy and growth. The small intestine has villi and microvilli that increase its surface area for efficient nutrient absorption. Choice A is incorrect because the large intestine, not the small intestine, primarily absorbs water. Choice C is incorrect as the large intestine, not the small intestine, stores waste. Choice D is incorrect because while the small intestine does produce some enzymes, its primary role is nutrient absorption.

Correct Answer: B

Rationale: When a sound wave travels from air to water, its speed decreases because sound travels faster in denser mediums. Water is denser than air, so the speed of sound decreases. This decrease occurs due to the change in the medium's properties affecting the wave propagation speed. The other choices are incorrect because the speed of sound is not dependent on frequency (choice D) and it doesn't remain the same (choice C) when transitioning between different mediums. Choice A is incorrect as an increase in density leads to a decrease in speed, not an increase.

Correct Answer: B

Rationale: The primary function of red blood cells is to transport oxygen. They contain hemoglobin, which binds to oxygen in the lungs and delivers it to tissues throughout the body. This process is essential for cellular respiration and energy production. Choice A is incorrect because while red blood cells do transport nutrients, their main role is oxygen transport. Choice C is incorrect because fighting infection is primarily the role of white blood cells. Choice D is incorrect as red blood cells do not produce antibodies; that is the function of specialized white blood cells called B cells.