Download The Time of Your Life

The Time of Your Life
You are to make a time line of YOUR growth and development.
Begin with your birth date, count back 266 days, this will be your date of conception.
Start with your date of conception and list important events and stages that you went through until
the present day. (My heart began to beat, my eyes started to develop, my fingers and toes began to
appear, I started crawling, walking, talking, etc.) Continue your outline to include important events
and stages that you will go through until you reach senescence (old age to death).
You must include major events, but you can include other events that you feel are important as well.
Genetics Activity
Genetics is the study of the mechanism of heredity. Stated another way, it is the study of ways traits
or characteristics are passes on from generation to generation. People differ from one another in by
the expression of these traits; thus, expressing their own individuality and uniqueness.
In this exercise, we will examine in more detail a few characteristics that are known to be controlled
by our genes. As we review several traits expressed in our bodies, circle the appropriate gene
symbols in the table below that apply to you.
TRAIT
Tongue roller
Widow’s peak
Free earlobe
Taste PTC
Straight thumb
Bent little finger
Mid-digital hair present
Dimples present
Short hallux
Short index finger
GENE SYMBOL
R
r
W
w
E
e
T
t
Hi
hi
Bf
bf
M
m
D
d
Ha
ha
S
s
TRAIT
Inability to roll tongue
Lack of Widow’s peak
Attached Earlobes
Inability to Taste PTC
Hitchhiker’s thumb
Straight little finger
Absence of mid-digital hair
Absence of dimples
Long hallux
Long index finger
Tongue Rolling
Attempt to roll your tongue into a U-shape, in which the sides of your tongue are curled upwards.
Tongue rollers carry a dominant R.
Widow’s Peak
A dominant gene W causes the hairline to form a distinct downward point in the center of the
forehead. Baldness will mask the expression of this gene.
Earlobe Attachment
The inheritance of a dominant gene E results in the free or unattached earlobe. If the lobe is attached
directly to the head, a recessive gene has been inherited. Other genes, working alone or together,
affect the size and shape of the earlobe.
Hitchhiker’s Thumb
Some individuals can bend the last joint of the thumb backwards at about a 45 degree angle. These
individuals are homozygous for a recessive gene but there is considerable variation in the
expression of the gene. For our purposes, we shall consider those who cannot bend at least one
thumb backwards at a 45degree angle to be carrying the dominant gene.
Bent Little Finger
The dominant gene causes the terminal bone of the little finger to angle toward the fourth (ring)
finger. Individuals whose little fingers are straight possess the homozygous recessive condition.
Check for this characteristic by laying your hands flat on the desk and relaxing them.
Mid-Digital Hair
The presence of hair on the middle segment of the fingers is caused by a dominant gene. The
homozygous recessive condition results in the lack or absence of hair on the middle segments.
Examine your hands closely and remember to mark your proper gene symbol in the table.
Facial Dimples
The inheritance of cheek dimples is controlled by a dominant gene. The recessive gene condition
lacks the ability to express facial dimples. Smile in the mirror or for a classmate to determine your
gene symbol.
Hallux Length
The length of the big toe (hallux) is governed by the Ha gene. Individuals whose hallux is shorter in
comparison to the second toe possesses the dominant gene. The inheritance of the homozygous
recessive results in the big toe being longer than or equal to the second toe.
Index Finger Length
Relax your right hand on this sheet of paper so that your middle finger lies on top of the line X
below and the end of your fourth finger (ring finger) is in line with line Y. If your second (index)
finger does not reach the top of the line Y or beyond, you have a short second finger in relationship
to the length of your fourth finger.
X
____________________________________ Y
PTC Tasting
Phenylthicarbamide (PTC) is a harmless chemical in small quantities. To individuals with the
dominant gene, it tastes undesirably bitter. Individuals who cannot taste PTC are homozygous
recessive. If you notice a bitter taste, then you are a taster of PTC.