Question

1. where are pigments found in hair?
2. how does the medulla differ between humans and animals?
3. what are the six different types of human hair?
4. how long does it take for materials in the body to present in hair? what kind of materials are tested for?
5. what are the racial groups hair is categorized by?
6. explain the differences in hair between these racial groups.

site 4:
google the following question: “how reliable is forensic hair analysis?” on the line above, write the address of the website you consult, and summarize what you find out below:

Explanation:

1. Hair pigments are found in the cortex. Melanin, the main pigment, gives hair its color and is located within the cells of the cortex.
2. In humans, the medulla is often fragmented or absent in fine - hair types, while in animals, it can be continuous, interrupted, or absent depending on the species. For example, some animals like rodents have a well - defined continuous medulla.
3. The six types of human hair are fine, medium, coarse, straight, wavy, and curly. These types are based on hair diameter and shape.
4. It can take about 7 - 10 days for new hair to start growing after a substance enters the body. Materials tested for in hair include drugs (such as cocaine, marijuana), heavy metals (like lead, mercury), and nutritional elements.
5. Hair is categorized by racial groups such as African - American, Asian, and Caucasian.
6. African - American hair is often more curly, with a flattened cross - section, Asian hair is typically straight and thick, with a round cross - section, and Caucasian hair can vary widely in texture from straight to curly and has a medium diameter.

For the forensic hair analysis question, reliable sources can include scientific journals or government forensic science websites. For example, the website of the National Institute of Justice (https://nij.ojp.gov/) may have information on the reliability of forensic hair analysis. Summaries often note that while hair analysis can provide some information like the presence of drugs or heavy metals, traditional microscopic hair comparison for identifying suspects has faced challenges in terms of reliability and has been re - evaluated in the light of DNA evidence development.

Answer:

1. In the cortex.
2. In humans, it can be fragmented or absent in some hair types; in animals, it can be continuous, interrupted or absent depending on species.
3. Fine, medium, coarse, straight, wavy, curly.
4. About 7 - 10 days; drugs, heavy metals, nutritional elements.
5. African - American, Asian, Caucasian.
6. African - American hair is often curly with a flattened cross - section; Asian hair is straight and thick with a round cross - section; Caucasian hair varies in texture and has a medium diameter.

Forensic hair analysis: Reliable sources may include https://nij.ojp.gov/; while it can detect some substances, traditional microscopic comparison for suspect identification has faced reliability challenges.