Download 3-23_Genetics

Warm-up
• Question:
1. Categorize the following traits: eye color, sun tan,
ear piercing, wavy/curly hair, hair color, attitude.
Acquired
Inherited
After today you should be able to
answer the following questions:
1. What is an allele?
2. What is the main difference between
genotype and phenotype?
What, How, & Where of Genes
• What are Genes?
– Genes are the “code” that determine our
inherited traits.
• How do we get genes?
– We get our genes from our parents.
• Where are genes found?
– All humans, animals, and plants have genes!
– Genes are found in your DNA. The DNA is
inside your chromosomes.
Genes are found in your DNA!
23
+ 23
= 46
(mom)
(dad)
chromosomes
How many possible combinations of 1 pair
of JEANS and 1 pair of SHOES?
1
2
3
4
FRAYER DIAGRAM: ALLELE
DEFINITION:
EXAMPLE:
CHARACTERISTICS:
ALLELE
PICTURE:
FRAYER DIAGRAM: ALLELE
DEFINITION:
CHARACTERISTICS:
Different versions
of the same
trait/gene
EXAMPLE:
ALLELE
PICTURE:
TRAIT/GENE: EYE COLOR
ALLELES: Blue, Brown, Green, Hazel…
TRAIT/GENE: HAIR COLOR
ALLELES: Brown, Red, Black, Blonde…
MOM
DAD
f
R
f
r
B
B
a
a
H
h
Q
q
D
d
J
j
GENES
Chromatid 1
ALLELES
Alleles are different
versions of the same
trait/gene
Chromatid 2
FRAYER DIAGRAM: ALLELE
DEFINITION:
CHARACTERISTICS:
Alleles are
Different versions
represented
using
of the same
CAPITAL & lowercase
trait/gene
letters.
EXAMPLE:
ALLELE
PICTURE:
MOM
DAD
f
R
f
r
B
B
a
a
H
h
Q
q
D
d
J
j
GENES
Chromatid 1
ALLELES
Chromatid 2
FRAYER DIAGRAM: ALLELE
DEFINITION:
CHARACTERISTICS:
Alleles are
Different versions
represented using
of the same
CAPITAL & lowercase
trait/gene
letters.
EXAMPLE:
ALLELE
B = Brown Eyes
b = Blue Eyes
PICTURE:
FRAYER DIAGRAM: ALLELE
DEFINITION:
CHARACTERISTICS:
Alleles are
Different versions
represented using
of the same
CAPITAL & lowercase
trait/gene
letters.
EXAMPLE:
ALLELE
B = Brown Eyes
b = Blue Eyes
PICTURE:
Let’s Review…
1.What are these two things?
2. Where did you inherit these from?
3. What do the colored squares
represent?
4. Why do we use capital and
lowercase letters?
ALLELES: Where do YOU stand?
1. What is an allele?
2. What do we use to represent alleles?
3. Draw a picture of two small chromatids.
Then, draw 3 different alleles on them
(DON’T FORGET THE LETTERS!).
ALLELES: Where do YOU stand?
1. Alleles are different versions of the same
trait/gene.
2. CAPITAL and lowercase letters!
3.
Genotype vs. Phenotype
Definition
Example
Memory
Trick
GENOTYPE
PHENOTYPE
combinations of
alleles in our
genes
physical
characteristics that
can be observed
Bb
G is your genes!
brown hair
P you can see!
Take a look at the following example…
Are they genotypes or phenotypes?
BB
Brown Eyes
Genotype
Rr
Genotype
RR
Phenotype
Tall
Genotype
Phenotype
Alleles can be DOMINANT or RECESSIVE
What is an allele?
Different versions of one gene!
What do we use to represent alleles?
CAPITAL and lowercase letters!
CONTEXT CLUES: DOMINANT
“I predict that Marquette will dominate North
Carolina in the Sweet 16 game on Friday.”
“He has a very dominant personality.
Whenever he speaks, no one else can be
heard.”
Stop and Jot: Write your own definition
CONTEXT CLUES: Recessive
“We are in an economic recession. The economy is
bad, so everybody has to cut back on the amount
of money they spend.”
“Since he turned 50, his hairline has started to
recede. His hair starts much farther back on his
forehead than it used to!”
“When the flood waters in New Orleans receded,
you could see how much damage Hurricane
Katrina had done.”
Stop and Jot: Write your own definition
Make a prediction:
What type of letter do you think
represents a DOMINANT allele?
UPPERCASE LETTERS!
What type of letter do you think
represents a RECESSIVE allele?
lowercase LETTERS!
2 Types of Alleles
DOMINANT
- The allele that is
always shown.
- Represented by
CAPITAL letters
2 Types of Alleles
DOMINANT
RECESSIVE
- An allele that only
- An allele that always
shows up in the
phenotype
shows up if there is
NO DOMINANT
ALLELE
- Represented by
CAPITAL letters
- Represented by
lowercase letters
Yellow body color is dominant to blue
Y = Yellow
y = Blue
YY =
Yellow
Yellow body color is dominant to blue
Y = Yellow
y = Blue
Y y=
Yellow
Yellow body color is dominant to blue
Y = Yellow
yy=
y = Blue
Blue
Square shape is dominant to round
S = Square
SS =
s = Round
Square
Square shape is dominant to round
S = Square
Ss =
s = Round
Square
Square shape is dominant to round
S = Square
ss =
s = Round
Round
Dominant vs. Recessive
1. What does dominant mean?
2. What does recessive mean?
3. Brown hair (B) is dominant to blonde hair (b).
a. If the genotype is Bb, what will the
phenotype be?
b. If the genotype is bb, what will the
phenotype be?
THE END
Bikini Bottom Genotypes and Phenotypes!
EXAMPLE (SpongeBob)
Trait: Pants Shape
Possible phenotypes:
_______: represented by “____”
_______: represented by “____”
Possible genotypes: __, ___, and ___
Possible outcomes:
___ ___ = _______________
___ ___ = _______________
___ ___ = _______________
Which phenotype is expressed? ____________
Which genotype do you predict he has? ___ ___
EXAMPLE (SpongeBob)
Trait: Pants Shape
Possible phenotypes:
_Square Pants_: represented by “__S___”
_Round Pants_: represented by “__s___”
Possible genotypes: __, ___, and ___
Possible outcomes:
___ ___ = _______________
___ ___ = _______________
___ ___ = _______________
Which phenotype is expressed? ____________
Which genotype do you predict he has? ___ ___
EXAMPLE (SpongeBob)
Trait: Pants Shape
Possible phenotypes:
_Square Pants_: represented by “__S___”
_Round Pants_: represented by “__s___”
Possible genotypes: _SS_, _Ss__, and _ss__
Possible outcomes:
___ ___ = _______________
___ ___ = _______________
___ ___ = _______________
Which phenotype is expressed? ____________
Which genotype do you predict he has? ___ ___
EXAMPLE (SpongeBob)
Trait: Pants Shape
Possible phenotypes:
_Square Pants_: represented by “__S___”
_Round Pants_: represented by “__s___”
Possible genotypes: _SS_, _Ss__, and _ss__
Possible outcomes:
S S = Square Pants
S s = Square Pants
s s = Round Pants
Which phenotype is expressed? ____________
Which genotype do you predict he has? ___ ___
EXAMPLE (SpongeBob)
Trait: Pants Shape
Possible phenotypes:
_Square Pants_: represented by “__S___”
_Round Pants_: represented by “__s___”
Possible genotypes: _SS_, _Ss__, and _ss__
Possible outcomes:
S S = Square Pants
S s = Square Pants
s s = Round Pants
Which phenotype is expressed? __Square Pants___
Which genotype do you predict he has? __S S__
Bikini Bottom Genotypes and Phenotypes!
QUIZ #17: REVIEW
In giraffes, the allele for brown spots (S) is
dominant. The allele for black spots (s)
is recessive. If a giraffe has black spots,
what GENOTYPE must it have?
ss
QUIZ #17: REVIEW
In palm trees, the allele for dark green
leaves (D) is dominant. The allele for
light green leaves (d) is recessive. If a
palm tree has light green leaves, what
GENOTYPE must it have?
dd
QUIZ #17: REVIEW
In butterflies, the allele for long antennae
(A) is dominant. The allele for short
antennae (a) is recessive. If a butterfly
has long antennae, what GENOTYPE
must it have?
AA or Aa
QUIZ #17: REVIEW
In butterflies, the allele for long antennae
(A) is dominant. The allele for short
antennae (a) is recessive. If a butterfly
has the genotype aa, what would be
the butterfly’s PHENOTYPE?
Short antennae
QUIZ #17: REVIEW
In Labrador retrievers, the allele for
yellow fur (Y) is dominant. The allele for
black fur (y) is recessive. If a Lab has the
genotype Yy, what would be the
PHENOTYPE of the lab’s fur?
Yellow fur
QUIZ #17: REVIEW
In tomato plants, the allele for tall plants
(T) is dominant. The allele for short
plants (t) is recessive. If a tomato plant
has the genotype tt, what would be the
plant’s height PHENOTYPE?
Short
QUIZ #17: REVIEW
INHERITED and ACQUIRED
traits – what’s the
difference? EXAMPLE?
Inherited traits are determined by your
genes (Example: height). Acquired traits
must be LEARNED (Example: math).
QUIZ #17: REVIEW
•
•
•
•
•
Eye shape
Intelligence
Hair color
Hair length
Accent (the way
you speak)
• Attitude
• Smile
• Tattoos
• Broken leg
• Face shape
• Diseases like
HIV/AIDS or
cancer
• Disorders like
albinism or colorblindness
• Hair texture
• Cheek size
trade & grade
QUIZ #17: REVIEW
What is an ALLELE? What do
we use to represent
alleles?
Alleles are different versions of the same
gene/trait. We use CAPITAL and
lowercase letters to represent them!
QUIZ #17: REVIEW
GENOTYPES and
PHENOTYPES – What’s the
difference? EXAMPLES?
Genotypes are combinations of your
alleles (Example: Bb). Phenotypes are
your physical characteristics (Example:
blue eyes).
QUIZ #17: REVIEW
DOMINANT and RECESSIVE
alleles – What’s the
difference? EXAMPLES?
Dominant alleles always show up
(Example: B=brown eyes). Recessive
alleles only show up if there is NO
dominant allele (Example: b=blue eyes).
QUIZ #17: REVIEW
In apple trees, the allele for green apples
(G) is dominant. The allele for red
apples (g) is recessive. If an apple tree
produces red apples, what GENOTYPE
must it have?
gg
QUIZ #17: REVIEW
In apple trees, the allele for green apples
(G) is dominant. The allele for red
apples (g) is recessive. If an apple tree
has the genotype GG, what would be
the PHENOTYPE of the apples
produced?
Green
How many possible combinations of
1 pair of JEANS and 1 pair of SHOES?
These baby girls are also TWINS and these are
their BIOLOGICAL parents!
How is that
possible?!
Skin color is
controlled by
6 different
genes!
This is called a
PUNNETT
SQUARE!
Y
B
R
R Y RB
P
PY PB
B
b
B BB
Bb
b Bb
bb
Invent-An-Alien!
Possible Phenotypes:
S/s: Square head (S) or Round (s)
E/e: Three eyes (E) or Five eyes (e)
H/h: Horns (H) or No horns (h)
G/g: Circle nose (G) or Triangle nose (g)
A/a: Two antennae (A) or Three antennae (a)
Y/y: Two eyebrows (Y) or Four eyebrows (y)
T/t: Sharp teeth (T) or Flat teeth (t)
1. Use these seven characteristics to invent and draw your alien.
2. Trade aliens with a partner.
3. On the back of your partner’s paper, draw two chromosomes, each
with seven alleles. Label each chromosome with the alien’s alleles!