The small, cone-shaped area at the base of the hair follicle that fits into the hair bulb is the:

Most of the total weight of hair comes from which layer of the hair?

Unique protein structures within the cortex are responsible for the color and ___ of hair.

Which of the following conditions is an autoimmune disorder?

Which condition is characterized by dry, sulfur-yellow, cuplike crusts on the scalp?

Hair that has the largest diameter and usually requires more processing time is:

The term used to describe abnormal hair loss is:

The ___ glands secrete sebum.

The two parts of a mature strand of human hair are:

Salt bond can be broken by ___ solutions.

How many hair growth treaments have been approved by the FDA for sale in the United States?

The technical term for brittle hair is:

Amino acids are joined by ___ bonds.

Disulfide bonds account for about ___ of the hair's overall strength.

The average hair density is about how many hairs per square inch?

Polypeptide chains are cross-linked like the rungs on a ladder by ___ different types of side bonds.

Hydroxide chemical hair relaxers break disulfide bonds and convert them to:

A helix is:

New hair is produced during the ___ phase, or growth phase, of hair growth.

Research has determined that dandruff is the result of a fungus called:

Proteins are made of long chains of:

An acute, localized bacterial infection of a hair follicle that produces constant pain, is called a boil or a:

Vellus hair almost never has a:

Trichorrhexis nodosa is the technical term for:

People with dry hair and scalp should:

The wave pattern of the hair refers to the ___ of the hair strand.