ati teas 7 science

Correct Answer: D

Rationale: The correct answer is D because all the options are valid obstacles to achieving controlled nuclear fusion on Earth. Lack of suitable materials (A) is crucial due to extreme conditions, limited fusion fuels (B) can hinder sustained reactions, and containing plasma (C) is challenging to prevent energy loss. Therefore, all factors must be addressed for successful fusion energy production.

Correct Answer: C

Rationale: The correct answer is C: Buffering system. The body maintains a relatively constant blood pH level through the buffering system, which involves the action of bicarbonate ions, carbonic acid, and other buffering molecules that help regulate pH by neutralizing excess acids or bases. This system acts quickly to prevent drastic changes in blood pH when there are fluctuations in blood carbon dioxide concentration. Cellular respiration (A) generates carbon dioxide, gas exchange (B) involves the exchange of gases in the lungs, and deoxygenation (D) refers to the loss of oxygen by the blood, but these processes are not primarily responsible for maintaining blood pH stability.

Correct Answer: B

Rationale: The correct answer is B: Ball-and-socket joint. This joint allows for the greatest range of motion due to its structure, where a rounded bone fits into a cup-like socket, enabling movement in multiple directions. This design permits flexion, extension, abduction, adduction, and rotation, providing a wide range of motion compared to other joint types. A: Hinge joints allow movement in one plane (like the elbow or knee). C: Pivot joints allow rotation around a central axis (like the neck). D: Saddle joints have more limited motion (like the thumb).

Correct Answer: A

Rationale: The correct answer is A: Hypothalamus. The hypothalamus plays a vital role in regulating body temperature by responding to internal and external temperature changes. It coordinates the body's response to maintain a stable temperature through processes like sweating or shivering. B: Cerebellum is responsible for coordinating movement and balance, not body temperature regulation. C: Pituitary gland regulates hormone production but not directly involved in body temperature regulation. D: Thyroid gland controls metabolism and energy levels but not primarily responsible for regulating body temperature.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver is responsible for detoxifying chemicals and metabolizing drugs due to its enzymes that break down substances. It also helps in excreting waste products. The kidneys (A) filter blood and regulate fluid balance. The heart (C) pumps blood throughout the body. The pancreas (D) produces digestive enzymes and insulin. Thus, the liver is the primary organ involved in detoxification and drug metabolism.