Which of the following best explains how the whorled patterns of fingerprints are associated with fetal blood supply during development?

• A. Fetal blood supply directly determines the genetic sequence responsible for fingerprint patterns.
• B. Variations in fetal blood flow influence the growth of skin ridges, leading to unique whorled fingerprint patterns.
• C. Whorled fingerprint patterns are formed solely by random cell migration, independent of blood supply.
• D. The presence of whorled fingerprints indicates a deficiency in fetal blood supply.

Answer: (B)

Verified step by step guidance

1. Understand the context: Fingerprint patterns, including whorled patterns, are formed during fetal development and are influenced by both genetic and environmental factors. The question asks about the role of fetal blood supply in this process.
2. Clarify the options: The first option suggests that fetal blood supply directly determines the genetic sequence, which is incorrect because genetic sequences are determined at conception and are not influenced by blood supply. The second option suggests that variations in fetal blood flow influence skin ridge growth, which aligns with current biological understanding. The third option claims that fingerprint patterns are formed solely by random cell migration, which oversimplifies the process. The fourth option suggests that whorled fingerprints indicate a deficiency in blood supply, which is not supported by evidence.
3. Explain the biological mechanism: During fetal development, the formation of fingerprints (dermatoglyphics) is influenced by the interaction of genetic factors and physical forces, such as the pressure and flow of blood in the developing dermis. Variations in blood flow can create localized differences in skin growth, leading to the unique ridge patterns observed in fingerprints.
4. Eliminate incorrect options: Since genetic sequences are not directly determined by blood supply, the first option is incorrect. The third option is also incorrect because fingerprint formation is not solely random but influenced by specific developmental factors. The fourth option is incorrect because whorled fingerprints are not indicative of a deficiency in blood supply.
5. Select the correct answer: The second option, which states that variations in fetal blood flow influence the growth of skin ridges, leading to unique whorled fingerprint patterns, is the most accurate explanation based on biological principles.