Santiago Callejas
Cherish Centeno
Romina Chanduvi
Aileen Perez
Since, dominant traits have “supremacy” over recessive traits, we have
created and conducted surveys that establishes whether dominant traits
are more common than recessive traits in the Miami-Dade College
Wolfson Campus student population.
If dominant traits prevail over recessive traits, then dominant traits should be
more “commonly” found in Miami Dade’s College student population.
Researched:
What are human traits?
Where do they come from?
Mendelian Genetics
Dominant VS Recessive
-Sex linked traits
- “Shuffling the deck”
Types of inherited human traits
-”
The genetically determined characteristic or condition of an individual.
These characteristics are controlled by one or more genes.
Most genes have two or more variations, called
alleles. For instance, the gene for hairline shape has
two alleles – widow’s peak or straight. An individual
may inherit two identical or two different alleles.
Straight Hairline
Widow’s Peak
Hairline
The eye color gene, also has
more than one variation.

Physical traits that are observable characteristics
determined by specific segments of DNA called
genes. Multiple genes are grouped together to
form chromosomes, which reside in the nucleus
of the cell.
•
Every cell (except eggs and sperm) in an individual's
body contains two copies of each gene. This is due
to the fact that both mother and father contribute a
copy at the time of conception.
This original genetic material is copied each time a cell divides so that all cells contain
the same DNA. Genes store the information needed for the cell to assemble
proteins, which eventually yield specific physical traits.
Mendelian Genetics
Mendel studied traits & how they are passed on to offspring
• He established 2 possible "alleles" for
each trait. The combination was (1 from
mom, 1 from dad) which is called your
"genotype"
• There are more than 2 alleles for some
traits. Most traits, in fact, are affected
by more than 1 gene
Gregor Mendel
(1822-1884)
Dominant Gene:
is expressed in a person who has only one
copy of that gene
Recessive Gene:
is expressed only when two copies of the gene
are present
2 Different Allele
-In heterozygous individuals, the allele that
is expressed is the “dominant” allele.
2 Matching Allele
-In homozygous individuals, The allele that is
expressed is either the “recessive” allele or the
“dominant” allele.
Sex-Linked Traits
Gregor Mendel
In the case of genes located on the X chromosome, females would have the usual 2
alleles for each gene but males only have 1 X chromosome and thus 1 allele (the Y
chromosome contains only a small number of genes related to gender)
Shuffling the Deck
(Gregor Mendel)
Chromosomes of offspring don’t have a half that’s clearly from dad and a half that's
from mom. During duplication there is "crossing over" of bits of each half.
Trait
Dominant
Recessive
Hairline
Widow’s peak
hairline
Straight hairline
Dimples
Dimples
No dimples
Earlobes
Detached Earlobe
Attached Earlobe
Freckles
Freckles
No freckles
Tongue
Roller
No roller
Thumb
Straight thumb
hitch-hikers
thumb
Who was surveyed?
Miami- Dade Wolfson Campus
Determining Factors: Race, gender and writing hand
Recessive Traits
Dominant Traits
-Straight hairline
-No dimples
-Attached Earlobe
-No roller
-hitch-hikers thumb
-Window’s peak hairline
-Dimples
-Free ear lobe
-Roller
-Straight thumb
Earlobe Trait
Race
Earlobes
50
45
40
35
30
25
20
15
10
5
0
White
Black
Attached
Detached
Earlobes
Dimples
Dimples
40
35
Dimples
30
25
Dimples
20
No Dimples
15
Race
10
5
0
White
Black
Race
Hairline Trait
Gender
Hairlines
Straight
Male
Widows Peak
Female
0
10
20
30
Number of people with hairline
40
Thumb Trait
Hitch-Hikers
Straight
Straight
Hitch-Hikers
Righty
Righty
Lefty
Lefty
Tongue Trait
Number of people with
tongue trait
Tongue Trait
40
35
30
25
20
15
10
5
0
Roller
Non-Roller
Black
White
Race
Results show that our hypothesis was indeed correct. They are more people within
the population who express dominant traits rather than recessive traits. However,
our studies also revealed that there are many among the population that display
recessive traits.
Dominant
Recessive
Straight Hairline
Attached earlobe
Straight Thumb
No Dimples
Tongue roller
1. Name a leading recessive trait found in the Miami-Dade student population.
A.
Freckles
B.
Dimples
C.
Tongue roller
D.
Attached earlobe
2. Is tongue rolling a dominant or recessive trait?
3. Who is going to get an A for the presentation
A.
Human traits group
B.
Human traits group
C.
Human traits group
D.
Human trait group