Transcript Genetics: Pass the Traits, Please

MUTATIONS
Weird Genetics
Mutations
A change in genetic
information
•Can occur randomly (naturally)
•Or can be deliberately caused in the laboratory by
scientists
•Inherited
•Not always harmful
http://www.accessexcellence.org/
Natural Mutations
These are not
albinos; they have
pigmented eyes.
White Bengal
Tiger
ALBINOS
• Little or no pigmentation in the eyes, skin, and hair (or
in some cases in the eyes alone).
• Inherited an altered copy of a gene that does not work
correctly.
• The altered gene does not allow the body to make the
usual amounts of a pigment called "melanin".
• True albinos have pink eyes and skin.
White Bluebonnets
Pink Bluebonnets
HUMAN
INTERVENTION
SELECTIVE
BREEDING
The selection of certain seeds
or animals for reproduction in
order to influence the traits
inherited by the next
generation.
SELECTIVE BREEDING
• The Liger is the result of breeding a female Tiger to a male Lion.
• The liger has both stripes and spots. The stripes are inherited
from its tiger parent and the spots from the lion parent.
• On their hind legs, ligers stand approximately 12 feet tall. At
most, ligers may weigh up to 1,000 pounds.
The Cama is the result of breeding a Llama to a
Camel.
Parents in background of picture.
The Zebroid is the result of
breeding
a female Horse and a male
Zebra.
The Zedonk / Zonkey is
the result of breeding
a female Donkey and male
Zebra.
Geep - These are the result of a sheep
and a goat.
The Mule is the result of breeding a female horse
(mare) to a male donkey (jack). The
mule is superior to the horse in strength,
endurance, intelligence and disease resistance.
Maroon & Red Bluebonnets
GENETIC
ENGINEERING
The selective, deliberate change of
genes (genetic material) by man.
The technique of removing, modifying
or adding genes to a DNA molecule in
order to change the information it
contains.
Bright face of genetically modified corn plant: pest-infected
non-GM (left) and pest-free GM plant (right) planted side-byside in a field trial. (photo: Dr. Yu Jialin, China Agricultural
University)
French genetic researchers created Alba for artist Eduardo Kac. Thanks to genes
borrowed from a jellyfish, the albino rabbit glows green when placed under special
lighting. In regular light, Alba appears like any other furry white rabbit. But place her
under a black light, and her eyes, whiskers and fur glow a otherworldly green.
"Glow in the dark" fish. these genetically modified fish were developed by a Taiwanese
aquatic firm, Taikong Group. They are planning to reproduce these fish in numbers and
sell them for pets.
http://www.fluorescentpets.com/index.htm
Scientists in the agriculture department of the Hebrew University in
Rehovot have genetically engineered a chicken that has no feathers.
Who Gets the
Money??
$$’s
$$’
$$’
s
Purpose: To solve a mystery using
genetics.
Las Vegas Sun Times:
Mr. and Mrs. Jones died in a tragic farm accident
when the tractor they were riding on overturned in
a ditch. Authorities found one million dollars
hidden in a feed bin in the chicken coop. The
couple is known to have a son, from whom they
are estranged. This man is the sole heir to the
Jones fortune.
The Mystery
• Five men show up, each claiming to be the
Jones’s long lost son who had run away to
become a circus clown. You are called in as a
genetics expert to decide who is the rightful
heir. This mystery will be solved in three parts.
Punnet Squares
• Female genotype always goes on top.
• Male genotype always goes on the side.
Part One: Monohybrid Cross
• Brown eyes are dominant over blue eyes, free
earlobes are dominant over attached earlobes.
• Use “B” for dominant eyes, “b” for recessive
• Use “E” for dominant earlobes, “e” for
recessive earlobes
Mr. Jones
Homozygous free earlobes and homozygous brown
eye
Mrs. Jones
Heterozygous free earlobes and heterozygous brown
eyes
Carl
Homozygous brown eyes and homozygous attached
earlobes
Ray
Homozygous free earlobes and homozygous blue
eyes
Dale
Heterozygous free earlobes and homozygous brown
eyes
Earl
Heterozygous free earlobes and heterozygous brown
eyes
Robert
Homozygous free earlobes, homozygous blue eyes
Punnet Squares – for offspring
•
Earlobes
E
e
Eyes
+
B
B
E
EE
Ee
B
BB
BB
e
Ee
ee
b
Bb
Bb
75% free earlobes
25% attached
100% Brown
eyes
Genotypes for each person
Person
Mr. Jones
Mrs. Jones
Carl
Ray
Dale
Earl
Robert
Eye Color
BB
Bb
Bb
bb
BB
Bb
bb
Earlobes
Ee
Ee
ee
EE
Ee
Ee
EE
Which men can be eliminated by these traits?
Ray & Robert Eliminated
• Both Ray & Robert have blue eyes which is
homozygous recessive (bb). This is not a genotype
possible for any offspring of Mr. and Mrs. Jones.
• Now the lawyers order blood tests. The lawyers
also read that hair texture is inherited.
Part Two: Co-dominance &
Incomplete dominance
• Type “A” and type “B” are co-dominant
over type “O”
• Rh+ blood is dominant over Rh- blood
• Hair texture exhibits incomplete
dominance. Homozygous dominants (HH)
have curly hair, homozygous recessives (hh)
have straight hair, & heterozygotes (Hh)
have wavy hair.
Blood Type, Rh Type, & Hair
Symbols
•
•
•
•
•
•
•
•
IA denotes dominant type A
IB denotes dominant type B
IAIB denotes type AB blood
i denotes the recessive blood type O
R+ denotes dominant Rh+
r denotes recessive RhH denotes dominant hair texture
h denotes recessive hair texture
Mr. Jones
Homozygous type A blood,
heterozygous Rh+, straight hair
Mrs. Jones Heterozygous type B blood,
homozygous Rh+, wavy hair
Carl
Heterozygous type A blood,
heterozygous Rh+, wavy hair
Dale
Heterozygous type A blood,
homozygous Rh+, wavy hair
Earl
Type O blood, Rh-, straight hair
Punnet Squares – for offspring
•
Blood
IB
i
IA
I AI
IAi
Rh factor
R+ R+
Hair
H h
R+ R+R+R+R+
h
Hh
hh
r
h
Hh
hh
B
IA
I AI B I Ai
AB or A
R+r R+r
Rh+
50% straight
50% wavy
Genotypes for Blood type, Rh, & hair
Person
Blood
Type
Mr. Jones IAIA
Rh Type Hair
Texture
R+r
Hh
Mrs.
Jones
Carl
IBi
R+R+
Hh
IAi
R+r
Hh
Dale
IAi
R+R+
Hh
Earl
ii
rr
hh
Can anyone be eliminated with this information?
Earl eliminated!
• Earl has the wrong blood type and the
wrong Rh type to be an offspring of Mr. &
Mrs. Jones.
• The lawyers now order a vision test to check
for red-green color blindness. Red-green
color blindness is a sex linked inheritance.
Part Three: Sex-linked Inheritance
Mr. Jones
Color blind
Mrs. Jones
Homozygous for normal
vision
Carl
Color blind
Dale
Normal vision
Use XC to denote color blindness on the X
chromosome.
Punnet Squares for offspring
X
X
XC
XCX
XCX
Y
XY
XY
100% of the daughters will be carriers for color
blindness – heterozygotes
100% of all sons will have normal vision
Genotypes
Person
Vision
Mr. Jones
XCY
Mrs. Jones
XX
Carl
XCY
Dale
XY
So, who gets the money??????????
Dale Wins!!!!
• Dale has all of the genotypes that prove that
he is the sole heir of Mr. & Mrs. Jones.
• He has brown eyes and free earlobes
• He has type A blood, is Rh+, & has wavy
hair
• He has normal vision.
• He is rich!!