Which of the following best describes human hair: is it considered biotic or abiotic?

• A. Neither, because it is not classified as biotic or abiotic
• B. Abiotic, because it is made of keratin
• C. Abiotic, because it is not alive once it leaves the scalp
• D. Biotic, because it originates from living cells

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the definitions of biotic and abiotic. Biotic refers to anything that is or was part of a living organism, originating from living cells. Abiotic refers to non-living components of the environment, such as rocks, water, or air, which were never alive.
2. Step 2: Analyze the structure of human hair. Hair is composed primarily of keratin, a protein produced by living cells in the hair follicle. While the visible part of the hair (the shaft) is not alive, it originates from living cells.
3. Step 3: Consider the origin of human hair. Since hair is produced by living cells in the scalp and is a product of biological processes, it is classified as biotic.
4. Step 4: Address the incorrect options. Hair is not abiotic because it originates from living cells, even though the hair shaft itself is not alive. It is also not 'neither' because it clearly fits the definition of biotic.
5. Step 5: Conclude that the correct answer is 'Biotic, because it originates from living cells,' as this aligns with the biological definition of biotic components.