To treat a callus, you decide to shave off some of the excess epidermis. while doing this, you notice that there is no pain or bleeding. why wouldn't it cause pain to remove onky the superficial part of the epidermis? why wouldn't it bleed?

Callus refers to a hyper-keratinized skin. The formation of callus occurs at the time of hyperkeratinization of the epidermal dead cell. It is stretum carniosum epidermis layer and comprises dead cells, so it does not comprise sensory receptors and blood vessels.  

Due to this reason, there is no bleeding and pain in callus when one shave it off. It is usually developed due to pressure, friction, or other chemical, or physical irritation on the epidermal layer.  

the correct answer is sex-linked recessive.

i just took the test

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.