ati teas 7 science

Correct Answer: C

Rationale: The correct answer is C: Diffraction. Diffraction is the phenomenon that explains the bending of light waves as they pass around an obstacle or through an aperture. This occurs when light waves encounter an obstruction or opening that causes the waves to spread out and bend around the edges, leading to interference patterns. Refraction (A) is the bending of light as it passes through different mediums, not around obstacles. Reflection (B) is the bouncing back of light waves when they hit a surface. Dispersion (D) is the splitting of light into its component colors due to differences in wavelength. Therefore, based on the context of the question, diffraction is the most appropriate explanation for the bending of light in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Vitamin D. When the skin is exposed to sunlight, a form of cholesterol in the skin is converted into Vitamin D. This vitamin plays a crucial role in calcium absorption and bone health. Vitamin A is not synthesized in the skin but obtained through diet. Vitamin C is obtained from fruits and vegetables. Vitamin E is a fat-soluble vitamin found in nuts and seeds. In summary, only Vitamin D is synthesized in the skin upon sunlight exposure, making it the correct answer.

Correct Answer: A

Rationale: The P wave on an ECG represents atrial depolarization. During the cardiac cycle, the electrical impulse originates in the sinoatrial (SA) node, causing the atria to contract. This depolarization of the atria is reflected as the P wave on the ECG. This occurs before the ventricles depolarize (choice B), repolarize (choice D), or before the atria repolarize (choice C). Therefore, the correct answer is A because the P wave specifically represents atrial depolarization in the cardiac cycle.

Correct Answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle is found exclusively in the heart, allowing it to contract rhythmically and involuntarily to pump blood throughout the body. Smooth muscle (A) is found in organs like the intestines and blood vessels, not in the heart. Skeletal muscle (C) is attached to bones and responsible for voluntary movements, while voluntary muscle (D) is a general term that refers to skeletal muscle controlled voluntarily. Therefore, the unique characteristics of cardiac muscle make it the correct answer for this question.

Correct Answer: D

Rationale: The correct answer is D, the medium's properties. The speed of a wave in a given medium is determined by the properties of that medium, such as its density and elasticity. This affects how fast the wave can travel through the medium. Amplitude (A) is the height of a wave, which does not directly impact the speed of the wave. Wavelength (B) is the distance between two consecutive points of a wave, and while it can affect the wave's behavior, it does not solely determine its speed. Frequency (C) is the number of wave cycles that pass a point in a given time, which is related to speed but not the sole determinant. Therefore, the correct answer is D as the properties of the medium directly influence the speed of the wave.