Biology 2

Question 1

How many volar pads grow on each hand and where?

Answer 1

Eleven generally develop in each hand, one at each fingertip, four interdigital
pads at the bases of the fingers, one thenar pad at the ball of the thumb and
one hypothenar pad along the outside of the palm. Each foot also has 11
corresponding pads.

Question 2

What parts of volar pad development is determined by genetics?

Answer 2

The size, shape, and period of development

Question 3

What happens, in terms of FRS, when volar pads regress?

Answer 3

it forces the growing
cells to fuse together along the lines of stress caused by the collapse of the
volar pads.

Question 4

High an round volar pad shapes determines which pattern?

Answer 4

Whorl

Question 5

Asymmetrical ‘leaning’ volar pads determines which pattern?

Answer 5

Loop

Question 6

Low absent volar pads determines which pattern?

Answer 6

Arches

Question 7

Early volar pad development determines which pattern?

Answer 7

Whorls

Question 8

Late volar pad development determines which pattern

Answer 8

Arches

Question 9

Why are ridges unique?

Answer 9

Although there is a genetic link with patterns often being similar among
siblings because the path of any ridge results from chaotic stress, the ridge
details are specific to the individual. Since chaotic stress defines the
characteristics, as with anything else created by nature, no two will ever be
the same. This is why they are unique.

Question 10

What happens in weeks 0-6 of gestation?

Answer 10

General hand and finger development.

Question 11

What happens in weeks 6-9 of gestation?

Answer 11

Rapid volar pad growth. Paddle-like hands begin to
resemble hands with fingers. Volar pads begin to vary in
position, size and shape.

Question 12

What happens in weeks 10-11 of gestation?

Answer 12

Volar pads begin to recede or deflate. This initiates the
development of the primary friction ridges through basal
cell proliferation.

Question 13

What happens in weeks 14-15 of gestation?

Answer 13

Sweat glands form. Initial formation of friction ridges takes place. Ridges begin to
form in different parts of the receding volar pad and spread out to eventually join and form the patterns and minute details in our fingerprints. As volar pads recede and the
skin stretches and compresses, friction ridges develop at right angles to these stresses.

Question 14

What happens in weeks 15-17 of gestation?

Answer 14

Secondary ridges begin to form in the furrows between
primary ridges. They are found between every primary
ridge deep in the epidermis but contain no sweat glands.
This signals the end of primary ridge formation.
Dermal papillae begin to develop between the primary
and secondary ridge structures.

Question 15

What happens in weeks 19-20 of gestation?

Answer 15

Primary ridges are completed and can be seen on the
surface of the skin.

Question 16

What happens in week 24 of gestation?

Answer 16

Friction ridge formation is complete. The permanent
patterns of these mature friction ridges are the
fingerprints the individual will have throughout life and
after death.

Question 17

What is a unit comprised of?

Answer 17

Each unit is a cluster of cells
which pair with sweat gland and pore.

Question 18

How do ridge endings form?

Answer 18

As the hand grows in size new ridges form in the empty spaces. When the primary ridge formation stops. All ridges stop growing and fusing creating ridges endings. Sometimes creating dots if a new ridge is formed right before the stoppage of ridge growth. Ridge endings also form as a ridge gets closed in by other ridges (Hale 1952).

Question 19

How are bifurcations formed?

Answer 19

As ridges develop, they do not always form a
continuous curve, as growth stresses create ridge deviations that result in
bifurcations. Growth forces stretching the epidermis pull new ridge units
away from the primary ridge, thus creating the bifurcation.

Question 20

What is the mutation that causes the absence of fingerprints? Which gene is the mutation found in?

Answer 20

Adermatoglyphia
It is found in the SMARCAD1 gene. Which is autosomal and means one copy of the altered gene in each cell is enough to cause the condition. (most likely if someone has adermatoglyphia then one of their biological parents will also have the condition.

Question 21

Inflammatory phase

Answer 21

The inflammatory phase is the body’s natural response to injury. After initial wounding, the blood vessels in the wound bed contract and a clot are formed. Once this has been achieved, blood vessels then dilate to allow
essential cells (antibodies, white blood cells, growth factors, enzymes, and nutrients) to reach the wounded area and start the healing process.

Question 22

Proliferation phase

Answer 22

“During proliferation, the wound is ‘rebuilt’ with new granulation tissue, which is comprised of collagen and other components such as elastin, and into which a new network of blood vessels develops. Healthy granulation tissue is dependent on sufficient levels of oxygen and nutrients supplied by the blood vessels. Healthy granulation tissue is granular and uneven in texture.” (Basal cells duplicate sideways to repair basal layer. Dermis helps by pulling the the cells closer. This leads to puckering of permanent scars).

Question 23

Maturation phase

Answer 23

“Maturation is the final phase and occurs once the wound has closed. This phase involves remodelling of collagen. Cellular activity reduces and the number of blood vessels in the wounded area regress and decrease. This can last up to two years.”

Question 24

What are scars made of?

Answer 24

Scars are fibrous tissue (collagen) and can take over a year to mature or completely heal.

Question 25

John Dillinger

Answer 25

After one round of plastic surgery from which he was
extremely disappointed to find that he still looked the same, one of the
doctors suggested that he remove his fingerprints as a way to escape being
detected. Dillinger liked this idea and elected to undergo the painful
process of obliterating his fingerprints. Dillinger used acid to burn the tips
of his fingers in late May 1934. The procedure appeared to be successful,
but faint ridge markings were still visible on his fingertips after the full
healing process, as were seen after Dillinger’s death.

Question 26

Robert Phillips

Answer 26

He got a doctor to graft the skin from his chest on to the
tips of his fingers.

Question 27

‘Handsome Jack’ Klutas

Answer 27

“Handsome Jack” Klutas: He attempted to file down the small ridges on
his fingers, but he ultimately failed.

Question 28

Two people of Kate ‘Ma Barker’s Clan: Alvin ‘ Creepy’ Karpis and Ma’s son Freddy

Answer 28

They decided to remove their fingerprints, so they hired mob
physician Joseph P Moran to do the job. Moran was inexperienced in this
procedure and repeatedly hacked and knifed at their prints until the
gangsters couldn’t bear any more pain, but when their fingers finally
healed, the fingerprint ridges grew back to their original patterns.

Question 29

Gus Winkler

Answer 29

Mutilation caused the fingerprint pattern to change from a twin loop

Question 30

Examples of jobs where fingerprints end up worn but will grow back after stopping work for a period of time

Answer 30

Brick layers, Jobs involving paper handling etc.