DMIT Genetic & Developmental Basis of Fingerprints 1 — Questions and Answers
Question 1: During which week of fetal development do fingerprint ridge patterns begin to form?
- 6th to 8th week
- 10th to 16th week (Correct answer)
- 20th to 24th week
- 28th to 32nd week
Correct answer: 10th to 16th week
Fingerprint ridge patterns (dermatoglyphics) begin forming between the 10th and 16th weeks of fetal development and are permanent by the end of the second trimester.
Question 2: Which skin layer is primarily responsible for forming the ridge patterns seen in fingerprints?
- Hypodermis
- Epidermis (Correct answer)
- Dermis
- Stratum corneum
Correct answer: Epidermis
The epidermis, specifically the basal layer interacting with dermal papillae, forms the ridge patterns that create fingerprints.
Question 3: What is the primary reason identical twins have different fingerprints even though they share the same DNA?
- Different epigenetic methylation patterns
- Random environmental factors in the womb affecting ridge formation (Correct answer)
- Mutations occurring after fertilization
- Different maternal nutrition intake
Correct answer: Random environmental factors in the womb affecting ridge formation
Even identical twins share the same DNA, but minor differences in womb position, amniotic fluid pressure, and random developmental variation cause distinct ridge patterns to form.
Question 4: In dermatoglyphics research, the term 'Total Ridge Count' (TRC) refers to:
- The total number of fingerprints with loop patterns
- The sum of ridge counts across all ten fingers (Correct answer)
- The number of triradii found on all fingers combined
- The average ridge density per square centimeter
Correct answer: The sum of ridge counts across all ten fingers
Total Ridge Count (TRC) is calculated by summing the individual ridge counts from all ten fingers, and it is used as a quantitative measure in genetic studies.
Question 5: Which scientific field first established the study of fingerprint ridge patterns as a means of understanding human genetics and development?
- Forensic science
- Anthropology
- Dermatoglyphics (Correct answer)
- Biometrics
Correct answer: Dermatoglyphics
Dermatoglyphics, coined by Harold Cummins in 1926, is the scientific field dedicated to studying skin ridge patterns and their genetic and developmental significance.
Question 6: Chromosomal abnormalities such as Down syndrome (Trisomy 21) are often associated with which distinctive dermatoglyphic feature?
- Absence of whorls on all fingers
- A single palmar crease (simian line) (Correct answer)
- Radial loops on all ten fingers
- Extremely high total ridge count
Correct answer: A single palmar crease (simian line)
A single transverse palmar crease, known as the simian line, is a classic dermatoglyphic marker associated with Down syndrome (Trisomy 21).
Question 7: Which researcher is credited with coining the term 'dermatoglyphics' in 1926?
- Francis Galton
- Harold Cummins (Correct answer)
- Juan Vucetich
- Karl Pearson
Correct answer: Harold Cummins
Harold Cummins, an American anatomist, coined the term 'dermatoglyphics' in 1926 to describe the scientific study of skin ridge patterns.
DMIT Genetic & Developmental Basis of Fingerprints 1
During which week of fetal development do fingerprint ridge patterns begin to form?