Answer AND Explanation:
As light reflected from an external object enters the eye, it is refracted by the cornea, aqueous humour, the lens and vitreous humour so that an image is focused on the retina. The image is real, upside down and smaller than the object. The photoreceptor cells are stimulated by the reflected light and impulses are set off. The impulses are transmitted by neurons through the optic nerve to the optic region of the brain. The brain interprets the impulse as an upright impression of the object.
HIV in fact kills the immune system cells causing our body cannot fight off infections and diseases from entering our body. this creates our immune system to become weaken.
A dependent variable is how they are recording, measuring or keeping track of the science experiment their doing.
A independent variable is the things/types there using to compare what is the most/least affective in the experiment.
A controlled variable is something that stays the same in the experiment or a group/set used for comparison
