Cosmetology Trichology

Explanation
Trichology is the correct answer because it is the technical name for the study of hair. It focuses on the health and diseases of the hair and scalp, including its structure, growth, and characteristics. Trichologists are experts in diagnosing and treating hair and scalp conditions, and they often work closely with dermatologists to provide comprehensive care for hair-related issues. Hairology and cosmetology are not specific to the study of hair, while biology is a broader scientific field that encompasses the study of all living organisms.

Explanation
The hair bulb is alive because it contains living cells responsible for the growth and nourishment of the hair strand. The hair bulb is located at the base of the hair follicle and contains the dermal papilla, which supplies nutrients to the hair follicle and promotes hair growth. The hair strand itself is made up of dead cells that have been pushed up and out of the hair bulb. Keratin, on the other hand, is a protein that makes up the structure of the hair, but it is not alive.

Explanation
The cluster of cells in the epidermis from which the hair follicle forms is called the primitive hair germ. This is the initial stage of hair follicle development, where a group of cells come together to form the foundation of the hair follicle. The primitive hair germ eventually develops into the hair follicle, which is responsible for producing and growing hair strands. The root sheath, hair strand, and hair fiber are all components of the fully formed hair follicle, but the primitive hair germ is the specific cluster of cells that initiates the formation of the follicle.

Explanation
The root sheath of hair is typically oval or round in wavy or straight hair. This is because wavy or straight hair tends to have a more uniform and smooth texture, resulting in a rounded or oval shape of the root sheath. In contrast, kinky or curly hair has a more irregular and tightly coiled structure, which may lead to a different shape of the root sheath.

Explanation
The primitive hair germ is the correct answer because it is the initial structure that develops into a fully formed hair follicle. It contains the necessary cells and components that will eventually differentiate and mature into the various layers of the hair follicle, including the cortex, root sheath, and cuticle. Without the presence and nourishment of the primitive hair germ, the hair follicle cannot fully develop.