#### Transcript Unit 4, Day 3 - Da Vinci Schools

Unit 4, Day 2
Genetics & Human Development
Thu, Jan 17th (Block, 115 Min)
Fri, Jan 18th (Block, 100 Min)
Homework Due Today (0 min) - Stamp
• Mendelian Genetics YouTube Video Notes &
Problems (35.F)
Daily Question (35.A) – 5 min
• Describe what your ideal child
would look like and what they
would be good at (or what they
school, environment, family,
etc. Why do you want these
Essential Skills and Knowledge (35.A) –
1 min
• 2.1.D (Mendelian Genetics) I can describe the genetic
basis for Mendel’s laws of segregation and independent
assortment.
• 2.1.E (Punnett Squares) I can utilize Mendelian genetics
to create and analyze monohybrid and dihybrid
Punnett squares.
• 2.1.F (Phenotype and Genotype) I can predict the
probably outcome of phenotypes in a genetic cross from
the genotypes of the parents and mode of inheritance
(autosomal or X-linked, dominant or recessive).
Homework CFU – 3 min
• Question #1 – Set up a monohybrid Punnett Square and answer the
following problem: In guinea pigs, short hair, “S”, is dominant to
long hair, “s”. One guinea pig is “Ss” and one is “ss”.
• What is the probability percentage of guinea pig offspring that will
have short hair? Long hair?
• What is the probability percentage that the guinea pig offspring will
be homozygous dominant, heterozygous, or homozygous recessive?
Homework CFU – 5 min
• Question #2 – Set up a DIHYBRID Punnett Square
and answer the following problem: In guinea pigs,
black fur, “B”, is dominant to white fur, “b”, and
rough fur, “R”, is dominant to smooth fur, “r”.
• Cross a parent who is heterozygous for BOTH traits
with a parent that is homozygous dominant for
BOTH traits.
Investigation Before Explanation (6
min)
• Rock, Paper, Scissors, Lizard, Spock
dY
• We did Rock v. Paper in the video
• What would happen if things got more complex?
Just as that got complex…
• Genetics is more complex than Mendel thought
• There are a lot of exceptions to Mendelian
genetics.
Incomplete Dominance (5 min)
Teacher Notes
Student Practice
• Heterozygous genotype =
phenotypes BLEND (dom.
allele doesn’t fully inhibit)
• Cap, letters for both alleles!
1.
WW (white) snapdragon X
RR (red) snapdragon.
Genotypes & phenotypes of
offspring?
2. Two heterozygous
snapdragons are crossed.
Genotypes & phenotypes of
offspring?
Codominance (5 min)
Teacher Notes
Student Practice
• Heterozygous genotype =
shows both phenotypes at the
same time.
• Use capital letters for both
alleles!
3. A black cat (BB) is crossed
with a tan cat (TT).
Genotypes & phenotypes?
4. A tabby cat (BT) is crossed
with a tan cat (TT).
Genotypes & phenotypes?
Polygenic Traits (5 min)
Teacher Notes
• Det. by 2 or more gene pairs
• Ex: Immune system, skin
color, hair, eyes, weight.
• Bell curve.
5.
Flip a coin six times. Record
▫ ______ T, _______ H
6. Class Data
3 T, 3 H:
▫ 0 T, 6 H:
4 T, 2 H:
▫ 1 T, 5 H:
5 T, 1 H:
▫ 2 T, 4 H:
6 T, 0 H:
Multiple Alleles (5 min)
Teacher Notes
• More than 2 alleles for one
trait exist
• Blood type
▫ 4 possible phenotypes: A, B,
AB, O
▫ 3 alleles:
 IA = Type A (dom)
 IB = Type B (dom)
 i = Type O (rec)
7.
Homozygous Type A blood
(IAIA) X Homozygous Type B
blood (IBIB). Phenotype and
genotypes of offspring?
What is the result an
example of?
8. Heterozygous A blood (IAi) X
Heterozygous Type B blood
(IBi). Phenotype and
genotypes of offspring?
Karyotype
Teacher Notes
Student Practice
• Female = XX
• Male = XY
red-green color blindness, etc.
• XA or Xa
9. Child’s sex probability?
10. Female carrier of red-green
color blindness (XAXa) X
male non-carrier (XAY).
Probability of boys/girls
having it? Carriers?
11. Male with red-green color
blindness (XaY) X female
non-carrier (XAXA).
Probability of boys/girls
having it? Carriers?
Wrap-Up (2 min)
• Incomplete Dominance: Traits BLEND
• Codominance: Both phenotypes are shown
• Polygenic Traits: 2 or more gene PAIRS
• Multiple Alleles: More than 2 possible alleles for one trait
• Sex-Linked Traits: On the X chromosome
▫ There are Y-linked traits (ear hair), but the Y chromosome is
super small and it’s biggest purpose is to turn a female into a
male (all of us start as females!)
Project Activity (30 min)
• If you show the DOMINANT phenotype, assume you are
HETEROZYGOUS. (Recessive = homozygous recessive)
• For polygenic traits (skin color, hair color, eye color):
choose the most accurate one for you.
• There are some incomplete dominance traits: again,
choose the most accurate one for you.
• To determine the allele you pass onto your child,
flip a coin.
• In general, Heads = dominant, Tails = recessive.
• If you are homozygous recessive, you do not
need to flip the coin (100% chance).
• Example: XX (mom) and XY (dad)
▫ Only father flips, X = tails, Y = heads
▫ Mom will always pass on X allele
Examples
• Round face (RR, Rr) and square face (rr)
▫ You have a round face? Choose Rr, NOT RR
▫ You have a square face? Choose rr.
▫ If: Mom is Rr and Dad is rr
 Mom flips heads  R
 Dad doesn’t need to flip  r
Rr
• Curly hair (CC), Wavy (Cc), Straight (cc)
▫ Mom = CC, Dad = Cc
 Mom doesn’t need to flip  C
 Dad flips tails  c
Cc
Skin Color
Hair Color
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Very dark black (AABBCC)
Very dark brown (AABBCc)
Dark brown (AABbCc)
Medium brown (AaBbCc)
Light brown (AaBbcc)
Light tan (Aabbcc)
Pale white (aabbcc)
Black (AABBCCDD)
Very dark brown (AABBCCDd)
Dark brown (AABBCcDd)
Brown (AABbCcDd)
Light brown (AaBbCcDd)
Honey blond (AaBbCcdd)
Blond (AaBbccdd)
Very light blond (Aabbccdd)
White (aabbccdd)
Examples
• Skin Color
• Mom is dark brown (AABbCc)
▫ Mom doesn’t need to flip for “a” trait  A
▫ Mom flips for “b” trait  B
▫ Mom flips for “c” trait  c
• Dad is medium brown (AaBbCc)
▫ Dad flips for “a” trait  a
▫ Dad flips for “b” trait  B
▫ Dad flips for “c” trait  c
AaBBcc
3 Capitals =
Medium Brown
Baby’s Name
• Must be appropriate
• There are several baby names that are actually
illegal in our world. If need be, I can act as the
legal authority.
▫ Examples: Talula Does The Hula, Venerdi (Friday
in Italian), Brfxxccxxmnpcccclllmmnprxvclmnckssqlbb11116,
Gesher (Bridge in Norwegian), Chow Tow, Smelly
Head, @, Miatt (didn’t show if boy or girl), Anus,
Devil
If your partner is not in this class…
• You will compile your data later. Just do your
coin flips!
When you are finished…
• Answer the conclusion questions on page 46!
Digital Portfolio
• You must scan or type up this document as your
Work Time (30 min)
• Photos
• Journal Entries
Homework
• dp.davincischools.org/staff/blarkin
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“Homework Spring ‘13”
Reproduction and Prenatal Development
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