332A Hair Science and Structure 4

Question 1

What is the typical rate of hair growth per month on the human scalp?

Accepted Answer

1.25 cm

Answer

Scalp hair grows at an average rate of approximately 1.25 cm (half an inch) per month, or about 15 cm (6 inches) per year.

Question 2

Which amino acid is most responsible for the formation of disulfide bonds in hair?

Accepted Answer

Cysteine

Answer

Cysteine is a sulfur-containing amino acid. The sulfur atoms in two cysteine molecules bond together to form the strong disulfide bonds that give hair its shape and strength.

Question 3

What is the term for the degree of coarseness or fineness of individual hair strands?

Accepted Answer

Texture

Answer

Texture refers to the diameter or thickness of individual hair strands. It is classified as fine, medium, or coarse and affects how hair responds to chemical services.

Question 4

What does hair porosity refer to?

Accepted Answer

The ability of hair to absorb and retain moisture

Answer

Porosity is the hair's ability to absorb and retain moisture. It is determined by the condition of the cuticle layer — raised cuticles mean high porosity, flat cuticles mean low porosity.

Question 5

Which layer of the skin contains the hair follicle?

Accepted Answer

Dermis

Answer

Hair follicles are rooted in the dermis, the second layer of the skin. The dermis contains connective tissue, blood vessels, and the structures that support hair growth.

Red Seal Hairstylist 332A Practice Test

Red Seal Hairstylist 332A Practice Test

332A Hair Science and Structure 4