Question

multiple-choice question
what is hair composed of?
dead cells
melanocytes
lymphocytes
keratin

Explanation:

Hair is primarily composed of keratin, a type of protein. Additionally, the visible part of hair (the hair shaft) consists of dead cells that are filled with keratin. Melanocytes are cells that produce melanin (for hair color) and are not the main component of hair structure. Lymphocytes are a type of white blood cell involved in the immune system, not related to hair composition. So the correct options related to hair composition are "Dead cells" and "Keratin". But if we consider the main structural component, keratin is the key protein, and the hair shaft has dead cells. However, among the options, both "Dead cells" (the hair shaft is made of dead, keratinized cells) and "Keratin" (the protein that makes up the hair) are correct. But let's analyze each:

• Dead cells: The hair shaft (the part we see) is made of dead, keratinized epithelial cells.
• Melanocytes: These are cells in the hair follicle that produce pigment, not the main component of hair structure.
• Lymphocytes: Immune cells, not part of hair.
• Keratin: The protein that forms the hair, as hair is a keratinous structure.

So the correct options are "Dead cells" and "Keratin". But maybe the question expects the main component (keratin) or the cell nature (dead cells). Wait, actually, hair is composed of keratin (the protein) and the hair shaft is made of dead cells (keratinized cells). So both "Dead cells" and "Keratin" are correct. But let's check standard knowledge: Hair is made of a protein called keratin, and the hair shaft consists of dead, keratinized cells. So both options are correct. But maybe the question has multiple correct answers. Let's confirm: Hair structure - the hair shaft is composed of dead, keratinized cells (so dead cells) that are filled with keratin (the protein). So both "Dead cells" and "Keratin" are correct.

Answer:

A. Dead cells, D. Keratin