Questions

Convex mirror is used as rear view mirror in vehicles. Because the image is smaller, more image can fit onto the mirror, so a convex mirror provides for a larger field of view than a plane mirror. This is why they are useful.

Vitiligo is a condition in which the skin loses its pigment cells (melanocytes). This can result in discolored patches in different areas of the body, including the skin, hair, retina and mucous membranes.

Many disorders have been linked to vitiligo. They are::

Hashimoto thyroiditis,

Graves disease,

Addison disease and

diabetes mellitus,

alopecia areata,

pernicious anemia,

inflammatory bowel disease,

psoriasis, and

autoimmune polyglandular syndrome.

REM sleep i.e, Rapid Eye Movement sleep is also known as paradoxical sleep because the measures of the brain activity closely resemble waking consciousness, but the person is incapable of moving as the brain is in fully active mode that time.