Question

The uppermost layer in the epidermis is made up of
a. Langerhans cells
b. Melanin
c. Dead Cells
d. Rhodopsin

Answer 1

Hint: Skin is made up of three layers namely:
Epidermis: - the outermost layer of the body is the skin.
Dermis: - the middle layer is known as dermis. It is a thicker layer.
Hypodermis (subcutaneous fat): - the bottom most layer.

Complete answer:

Epidermis is the outermost layer of skin. The uppermost layer of epidermis is known as Stratum Corneum.
This layer is mostly made up of keratin and lipids. The cells in this layer usually have a 2-week life cycle. The cells shed in this layer and are replaced by cells of lower epidermis.
The cells of the uppermost layer of epidermis are flat, usually dead and are filled with keratin.
This layer protects the skin from light, water, heat, bacteria and chemicals. It also serves as the primary barrier between the body and the environment. It can be also known as horny layer as cells are tougher like animal horns.

Note: The cells in the stratum corneum are dead because this is a part of the natural life cycle of skin cells so they are continuously replaced.
The cells of this layer are dead because they are continuously replaced by lower layer epidermal cells. They are replaced when they are exposed to excess chemicals, water, sunlight etc. To repair this skin, they become dead and are replaced.
the outermost layer of the epidermis, the stratum corneum is the first line of defence for the body, serving an essential role as a protective skin barrier against the external environment. The stratum corneum aids in hydration and water retention, which prevents cracking of the skin, and is made up of corneocytes.