ati teas 7 science

Correct Answer: C

Rationale: The correct answer is C: Peripheral nervous system. This system consists of nerves that connect the sensory organs (such as eyes, ears, skin) to the central nervous system (brain and spinal cord). It transmits sensory information from these organs to the CNS for processing. The autonomic nervous system (A) controls involuntary functions, somatic nervous system (B) controls voluntary movements, and central nervous system (D) processes and integrates information but does not directly transmit signals from sensory organs.

Correct Answer: B

Rationale: Platelets are responsible for blood clotting, which is crucial for preventing excessive bleeding when a blood vessel is injured. They adhere to the site of injury and form a plug to stop bleeding. This function is essential for maintaining hemostasis in the body. Platelets do not carry oxygen like red blood cells (Choice A), fight infection like white blood cells (Choice C), or transport nutrients like plasma (Choice D).

Correct Answer: B

Rationale: The correct answer is B: Pulmonary artery. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. This is a crucial step in the pulmonary circulation system. The pulmonary vein carries oxygenated blood from the lungs back to the heart, so it does not transport blood from the heart to the lungs. The aorta is responsible for carrying oxygenated blood from the heart to the rest of the body, not to the lungs. The superior vena cava is a large vein that carries deoxygenated blood from the upper body to the heart, not to the lungs. Therefore, the pulmonary artery is the correct choice for transporting blood from the heart to the lungs.

Correct Answer: B

Rationale: The correct answer is B: Nucleotide. Nucleotides are the building blocks of DNA, consisting of a sugar molecule, a phosphate group, and a nitrogenous base. They are linked together in a specific sequence to form the DNA molecule's double helix structure. Amino acids (choice A) are the building blocks of proteins, not DNA. Phosphate groups (choice C) are components of nucleotides but are not the sole building blocks of DNA. Fatty acids (choice D) are not involved in the structure of DNA at all. Therefore, the correct answer is nucleotide as it accurately represents the basic components that make up DNA.

Correct Answer: B

Rationale: The correct answer is B: Protons and neutrons only. Electrons are not found in the nucleus, as they orbit around the nucleus in electron shells. Protons and neutrons are the subatomic particles found within the nucleus of an atom. Protons have a positive charge, while neutrons are neutral. The nucleus contains almost all of the atom's mass and is positively charged due to the presence of protons. Choice A is incorrect because electrons are not part of the nucleus. Choice C is incorrect because electrons are not present in the nucleus. Choice D is incorrect as protons and neutrons are indeed constituents of the atomic nucleus.