Year 8/7th Grade Exam Quiz :) Science

Heart disease is not caused by lack of Vitamin C. Heart disease is a complex condition that can have multiple causes, including high blood pressure, high cholesterol, smoking, obesity, and a sedentary lifestyle. While Vitamin C is important for overall health and can help support a healthy cardiovascular system, it is not the sole cause of heart disease. Other factors such as genetics, age, and underlying medical conditions also play a significant role in the development of heart disease.

Light travels in straight lines because it is a form of electromagnetic radiation that propagates through space as waves. These waves move in a straight line until they encounter an obstacle or are refracted or reflected by a medium. This behavior is explained by the principle of rectilinear propagation of light, which states that light travels in straight lines unless it interacts with another object or medium.

The word equation for respiration is glucose + oxygen = carbon dioxide + water. During respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide and water. This process releases energy that is used by cells for various functions.

Refraction is the correct answer because when light passes through a window, it changes direction due to the change in speed caused by the change in medium. This phenomenon is known as refraction.