ati teas 7 science

Correct Answer: C

Rationale: The correct answer is C: Light energy from the sun. This is because photosynthesis, the process by which plants and other organisms convert light energy into chemical energy, is the primary source of energy in most ecosystems. Sunlight is essential for plants to produce food, which then sustains the entire food chain. Choice A (Chemical energy stored in bonds) is incorrect because this energy is a product of photosynthesis and not the primary source entering ecosystems. Choice B (Thermal energy from the Earth's core) is incorrect as it is not a significant source of energy for most ecosystems. Choice D (Kinetic energy from wind and water) is also incorrect as it is not the primary source of energy entering ecosystems, although it can play a role in some ecosystems.

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. Sunscreen protects the skin by absorbing UV rays and converting them to heat. This process prevents the UV rays from penetrating the skin and causing damage. Reflecting UV rays (A) would not be as effective as absorbing them. Blocking UV rays completely (C) is not possible with sunscreen. Stimulating melanin production (D) is not the main mechanism of how sunscreen works to protect the skin.

Correct Answer: C

Rationale: The correct answer is C: Total lung capacity. Total lung capacity is the maximum volume of air the lungs can hold after a full forced inhalation. It includes all the volumes within the lungs, such as tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. It is the sum of vital capacity and residual volume. Inspiratory capacity (A) is the maximum volume of air that can be inhaled after a normal exhalation. Tidal volume (B) is the volume of air inspired or expired during normal breathing. Vital capacity (D) is the maximum volume of air that can be exhaled after a maximum inhalation, not the total volume the lungs can hold.

Correct Answer: C

Rationale: The correct answer is C: Vitamin K. Vitamin K is essential for blood clotting as it helps in the synthesis of clotting factors. Without adequate vitamin K, the blood cannot clot properly, leading to excessive bleeding. Vitamin A (Choice A) is crucial for vision and immune function, not blood clotting. Vitamin C (Choice B) is important for collagen synthesis and immune function, not blood clotting. Vitamin D (Choice D) is essential for bone health and immune function, not blood clotting. Thus, the correct choice is Vitamin K as it plays a direct role in the blood clotting process.