exploring dominant and recessive traits...each person has about 70,000 pairs of genes. genes can be...
TRANSCRIPT
Exploring
Dominant and
Recessive Traits
Where do traits come from?
Your parents pass them down through genetic traits.
You receive half of your genes from each parent
Each person has about 70,000 pairs of genes.
Genes can be dominant or recessive
Dominant Traits vs.
Recessive Traits
Dominant trait-Strongest trait
Dominant trait-Masks or covers up the weaker trait
Common Misconception
Recessive Traits are not rare traits.
Dominant or recessive traits may be more common in a
population.
Example: Blonde hair is very common in parts of
Scandinavia.
Example: The trait of having six fingers on one hand is a
dominant trait!
DNA fun facts
How long does it take one of your cells to completely copy its DNA?
8 hours
In the human DNA code is made up of base pairs: A-T and G-C on each side of the DNA strand. How many base pairs are in a DNA strand?
3 billion
If you were to recite the order of the ATCGs in your DNA starting tomorrow morning, at a rate of 100 nitrogen bases per minute, how long would it take you to recite one entire DNA strand if you didn’t stop to eat, drink, sleep or go to the bathroom, etc?
57 years
DNA fun facts
Autosomal cells have how many chromosomes?
46
Sperm and egg have how many chromosomes?
23
If you were to stretch out the DNA from your 46 chromosomes in just one cell and lay it end to end, how long would it be?
Over 2 yards
If the total DNA in one person were laid out in a straight line, how long would it be?
30 times the distance to the sun
DNA fun facts
How many cell nuclei could you fit across the period on
your paper?
1000
How many threads of DNA could you fit across the same
period?
1 million
If you wanted to store all the information from a strand
of DNA on a computer, how much storage space would it
take up?
3 GB
DNA fun facts
How genetically similar are you to any other
random human on the planet? (percentage wise)
99.9%
How much genetic material do we as humans share
with the bacteria e. coli? (percentage wise)
7%
How much genetic material do we as humans share
with earthworms? (percentage wise)
21%
DNA fun facts
How much genetic material do we as humans share with the a zebra
fish? (percentage wise)
85%
How much genetic material do we as humans share with a mouse?
(percentage wise)
90%
How much genetic material do we as humans share with a chimpanzee?
(percentage wise)
98%
What percent of our DNA codes for proteins?
2%
The dominant trait is always the better trait to have.
False
Help!
An alien from outer space teleports into the class. Upon
seeing the class,
the alien concludes that all humans look alike. It is your
job as a class to assist the alien in differentiating
humans from each other.
Form a list with the people around you.
On a sheet of paperYes Class Frequency No Class Frequency
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Earlobe
Darwin’s Ear Points
Dimples
Tongue Rolling
Left handed
Freckles
Widows Peak
Curly Hair
Longer 2nd toe
Hair Color
Eyes
Thumb
Butt Chin/Cleft Chin
Skin Pigment
Vision
Tongue to Nose
Mid-digit hair
Dominant Recessive
Index finger longer than ring finger
Bent little finger
Hand Clasping
Vulcanism
Questions to think about
Which traits are most common in your class? Least common?
Create a bar graph of the classroom responses.
What evidence (data) suggests that humans are similar?
Different?