Science TEAS Practice Test

Correct Answer: B

Rationale: The correct answer is B: A gene. A gene is the smallest unit that can encode for a trait because it is a specific sequence of nucleotides in the DNA that provides instructions for a particular trait or function. Genes determine our physical characteristics and traits. A codon (choice A) is a sequence of three nucleotides that code for a specific amino acid in protein synthesis, not a complete trait. A nucleotide (choice C) is the basic building block of DNA, but it is not capable of encoding for a trait on its own. A chromosome (choice D) is made up of DNA and contains multiple genes, so it is not the smallest unit that can encode for a trait.

Correct Answer: D

Rationale: The correct answer is D: Help red blood cells transport oxygen. Hemoglobin is a protein in red blood cells that binds to oxygen in the lungs and releases it in tissues. It does not transport oxygen itself, but it aids red blood cells in carrying oxygen. Choice A is incorrect because hemoglobin carries oxygen, not transports it. Choice B is incorrect because hemoglobin binds to oxygen, not to red blood cells. Choice C is incorrect because hemoglobin primarily transports oxygen, not carbon dioxide.

Correct Answer: B

Rationale: The correct answer is B: Tendons. Tendons are fibrous connective tissues that attach muscle to bone, allowing for movement. Ligaments (A) connect bone to bone, muscles (C) are the tissues responsible for movement, and bones (D) are the rigid structures that make up the skeletal system. Tendons play a crucial role in transmitting the force generated by muscles to move bones, making them the correct choice in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Circulatory system. This system, composed of the heart, blood vessels, and blood, is responsible for transporting nutrients, gases, and wastes throughout the body. The heart pumps blood carrying oxygen and nutrients to cells and removes waste products. The blood vessels distribute these substances to tissues and organs. The respiratory system (A) is responsible for gas exchange but not for transporting nutrients and wastes. The digestive system (B) processes food and absorbs nutrients but does not transport gases. The nervous system (D) coordinates body functions and transmits signals but does not transport nutrients, gases, or wastes.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver is primarily responsible for detoxification in the body as it processes and removes toxins, drugs, and other harmful substances from the bloodstream. It metabolizes these toxins into less harmful compounds that can be excreted from the body. The kidney, although important for filtering waste and regulating electrolytes, is not primarily responsible for detoxification. The lung primarily functions in gas exchange, and the heart is responsible for pumping blood throughout the body, not for detoxification. Therefore, the liver is the correct choice for the organ primarily responsible for detoxification.