Name
Period
Date
INTEGUMENTARY IDENTIFICATION
An organism’s DNA codes for every single trait present. Cells, skin, & hair all have specific features
that belong only to the individual from which they came. These unique characteristics remain
absolutely the same during your entire life. Therefore, integumentary structures can be used to
identify an individual.
PROBLEM
How are the tissues of your integumentary system unique?
PART A: BARR BODIES
Barr bodies are darkly staining structures attached to the nuclear membrane visible in female cells.
They are the result of one X chromosome being inactivated. Barr body testing was used in the
Olympic games from 1966 until 1992 as a gender verification test, in an effort to detect male atheletes
trying to “pass” as females. Six female competitors failed the test in the 1984 Los Angeles Olympic
games.
1. Place a drop of methylene blue solution on a clean slide.
2. Gently scrape the inside of your cheek with the flat end of a clean toothpick and then stir the
toothpick end in the methylene blue. Place a coverslip over the mixture.
3. The stain methylene blue should reveal the nucleus and (in females) the Barr bodies, which
are inactivated forms of X chromosomes.
4. Using both low and high magnifications, try to identify the nucleus, the darkly staining
nucleolus, the nuclear membrane, the plasma membrane, and the cytoplasm.
5. Draw a male buccal cell & a female buccal cell in the space provided. LABEL the nucleus,
nucleolus & Barr body where appropriate.
PART B: FINGER PRINTS
The upper region of the dermis is characterized by parallel rows of peglike projections called dermal
papillae. These upward projections form the ridges & grooves that create a unique fingerprint.
Fingerprints offer an infallible means of personal identification because the pattern is maintained
throughout life, changing only in size as the body grows.
6. On a separate sheet of paper, make a pencil smudge.
7. Rub your right thumb in the smudge.
8. Gently press transparent tape over your right thumb, and then gently remove the tape. Place
the tape in the appropriate box below.
9. Repeat the procedure with the rest of your fingers.
10. Label your prints arch, loop, or whorl.
Thumb
Pointer
Middle
Ring
Pinkie
Right Hand
Left Hand
Class Statistics:
Record information for the RIGHT, POINTER finger of each student in the class.
# w/ Loops = _______
_______
% w/ Loops = _______
# w/ Whorls = _______
% w/ Whorls = _______
# w/ Arches = _______
% w/ Arches = _______
Total # =
PART C: LIP PRINTS
Like fingerprints, no two lip prints are exactly the same. The study of lip prints is called cheiloscopy.
Many people’s lips have parts of at least two patterns. This allows for great variety between the lips of
different individuals. Lip prints are collected from crime scenes in much the same way as fingerprints.
However, the use of lip prints in criminal cases is limited because the credibility of lip prints has not
been firmly established in court.
11. Use a q-tip to apply lipstick or lip balm to your lips. Red lipstick works the best!
12. Fold an index card in half and press your lips on the crease. Unfold and label with your name.
13. Examine the lip print closely with a magnifier. Sketch your lip print in the space provided. Pay
attention to the shape and direction of the lines created by your lips.
Sketch of lip print
PART D: HAIR PATTERNS
A hair is composed of three distinct
layers: cuticle, cortex, & medulla.
The cuticle is the hard outside covering
made of overlapping scales (cells) pointing
toward the tip. There are many different
types & arrangements of cuticle scales,
varying from loose, open scales to tight,
firm scales. The medulla of a hair is made
of cells that run through the center of the
cortex like a canal. The medulla may not
be a continuous canal; it can be
interrupted, fragmented or absent.
Notes on patterns in lip print
14. Obtain a sample of your hair & place it on a clean slide. Add a drop or two of water & cover
with a coverslip.
15. Use the low power objective to locate the hair & then switch to high power.
16. Sketch the hair & note the appearance of the medulla in the table below.
17. Switch slides with someone who has different hair than yours (thicker, thinner, darker, lighter,
straight, curly, etc.) Draw a picture in the appropriate location.
18. If you have extra time, observe hairs from various locations on your body (arm, leg, eyelashes,
eyebrows…)
Sketch of your hair
Sketch of different hair
Appearance of medulla:
Appearance of medulla:
ANALYSIS
1. Use your knowledge of genetics to explain why Barr bodies are only present in the cell nuclei
of females.
2. What are some reasons a parent might want to have their child fingerprinted?
3. Do you think lip prints should be used as evidence in court cases? WHY or WHY NOT?
4. List three ways that your hair differed from the person’s hair with whom you compared.