It radiates light and heat, or solar energy, which makes it possible for life to exist on Earth. Plants need sunlight to grow. Animals, including humans, need plants for food and the oxygen they produce. Without heat from the sun, Earth would freeze.
Significance of the birds in the old man
<span>D.Oxygen will diffuse from an area of higher concentration (outside the cell) to an area of lower concentration (inside the cell). This is because cells respire constantly, as this process uses up oxygen cells will contain less oxygen than its surroundings. Oxygen moves by the process of diffusion, in diffusion a molecule will always move from a higher concentration to a lower concentration.</span>
