Bio 9B: Tuesday, 3.22.11
Title: Introduction to Genetic Inheritance and Variation

Homework:


Complete the Making Babies Analysis Questions
Silent Do Now: (in notebook w/ title and date)
What is the difference between a gene and an allele? (Check your
notes from last week if you don’t remember)
 How do you think a dominant allele is different from a recessive
allele? What do you think dominant and recessive mean?
 Predict what you think genotype and phenotype mean (these are
new words we will learn today)
 Hand in Modeling Meiosis packet and Karyotyping Part II packet if
you didn’t hand them in yesterday
Today’s Objectives:
 Use genetics vocabulary to describe genes and alleles
 Differentiate between genotypes and phenotype
 Experiment with probability to see the diversity of offspring that can be
made through sexual reproduction


Double Block
Agenda
Introduction to new Genetics Terms (10 min)
 Makin’ Babies Activity
 Explanation (5 minutes)
 Activity (25 minutes)
 Post picture of the Baby on the front board
 Introduction to Punnett Squares/ Monohybrid
Crosses (15 Min)
 Making Babies Probability w/ clickers (15 min)
 Making Babies Analysis Questions (20 min)

MENDELIAN GENETICS:
THE STUDY OF GENETIC
INHERITANCE PATTERNS
Biology 9: Moretti / Dickson
Genetics Overview


Genetics is the study of gene inheritance and
variation
Genetics answers big questions like:
 How
are traits inherited?
 Why do offspring look similar to their parents but not
exactly like their parents?
 How do we have so many different types of organisms
and so much genetic variation?
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Genetics Vocabulary:
Gene:
A section of DNA that encodes a particular protein (ex: hair
protein)
Alleles:
Different versions of a gene (ex: black hair vs. blond hair)
Everyone has two alleles for each gene – one from each
parent!
Mendelian Genetics and Probability

New Vocabulary:

Dominant and Recessive
 Dominant:
 The allele
that is always expressed as a trait if it is
present (regardless of other alleles)
 Recessive:
 The allele that is only expressed as a trait if the dominant
allele is not present
Evidence:
True-breeding yellow x True-breeding green
(YY)
(yy)
All yellow offspring
(Yy)
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Mendelian Genetics and Probability

New Vocabulary:

Genotypes and Phenotypes
 Genotypes:
 The genetic make-up of an
 The combination of alleles
organism
 Phenotypes:
 The
expressed physical
characteristics
 The “Trait”
“Phenotypes are the sum of Genotypes +
Environment”
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
“Makin’ Babies”:
Mendelian Genetics and Probability
Step 1: Genotype Data Table”
Determine the Traits of your baby by flipping the coin a total of
two times for each trait (once for each allele).
Heads = Dominant and X
Tails = Recessive and Y
Example: Face shape = R, so heads=R and tails = r
Write the combination of the alleles in the box next to the trait. This
is the Genotype for each trait
Step 2: Phenotype chart
Determine the Phenotype based on the Genotype from page 1
Example: if you flipped two RR for face shape, the phenotype would be
Round
Step 3: Draw your baby by using the traits from the Phenotype chart
More Genetics Vocabulary

Homozygous and Heterozygous
 Homozygous:
Two of the same allele for a
particular trait are present
 Ex:
RR (homozygous dominant) = Round Face
 Ex: rr (homozygous recessive)= Square Face
 Heterozygous:
Two different alleles for a
particular trait are present
 Ex:
Rr = Round Face
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Making Babies – Predicting Probabilities
In the activity, the mother and father were both
heterozygous for each trait
Mother was Rr
Father was Rr
half of the sperm got each allele
½ of Mom’s
eggs got the R
allele
½ of Mom’s
eggs got the r
allele
R
r
R
RR
Rr
r
Rr
rr
Making Babies – Predicting Probabilities
This Punnett Square is used to PREDICT PROBABILITIES,
NOT to tell you the actual numbers you will get!
Probability of Round Face (RR or Rr)
= ¾ or 75%
Probability of Square Face (rr)
= ¼ or 25%
R
r
R RR
Rr
Rr
rr
r
Now let’s make predictions for the sex
of the baby (boy or girl?)



Mother’s genotype: XX
Father’s genotype: XY
Make a Punnett Square and fill it in
X
Y
Chances of girl
(XX)
= ½ or 50%
X
XX
XY
Chances of boy
(XY)
= ½ or 50%
X
XX
XY
Your Clicker Number:
Write it on the FRONT of your notebook
Clicker
Number
1
2
3
4
5
6
7
8
9
10
11
12
Student Name
Israel
Patrick
Trevon
Jamesley
Nancy
Zuri
Andre
McHenley
Aser
Emily
Harold
Natalie
Clicker
Number
13
14
15
16
17
18
19
20
21
Student Name
Ricardo
Whitney
Grace
Thomas
Natalie
Leslie
Emperor
Julian
Larissa
Now let’s see if the class’s babies match our
predicted probabilities!

Take out the Making Babies packet and turn to the very back page

We will use clickers to collect data for Analysis Question #5

Calculate Expected Ratios for the following traits
Trait
EXPECTED
Ratio
Face
Shape
75%, 25%
Cleft Chin 75%, 25%
Widow’s
Peak
75%, 25%
Earlobes
75%, 25%
Gender
50%, 50%
PERCENT of Babies PERCENT of Babies
with Dominant
with Recessive
Phenotype
Phenotype
Phenotype Class Results:
What is the face shape of your baby?
1.
2.
Round (dominant)
Square (recessive)
76%
24%
1
2
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Phenotype Class Results:
Does your baby have a cleft chin?
1.
2.
No, it’s absent (dominant)
Yes, it’s present (recessive)
86%
14%
1
2
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Phenotype Class Results:
Does your baby have a widow’s peak?
1.
2.
Yes, it’s present (dominant)
No, it’s absent (recessive)
64%
36%
1
2
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Phenotype Class Results:
What kind of earlobes does your baby have?
1.
2.
Unattached (dominant)
Attached (recessive)
82%
18%
1
2
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Phenotype Class Results:
What is the gender of your baby?
1.
2.
Girl (XX)
Boy (XY)
59%
41%
1
2
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Now let’s see if the class’s babies match our
predicted probabilities!


Take out the Making Babies packet and turn to the very back page
We will use clickers to collect data for Analysis Question #5
Trait
EXPECTED
Ratio
Face
Shape
75%, 25%
Cleft Chin 75%, 25%
Widow’s
Peak
75%, 25%
Earlobes
75%, 25%
Gender
50%, 50%
PERCENT of Babies PERCENT of Babies
with Dominant
with Recessive
Phenotype
Phenotype
Making Babies – Analysis Questions


Answer all questions on a separate piece of paper
This is HW due tomorrow!
Bio 9B: Wednesday, 3.23.11
Title: No Class – Half Day

Homework:

Do Now:

Today’s Objectives:
Bio 9B: Thursday, 3.24.11
Title: Genetic Inheritance & Variation - Mendel’s Principle of Segregation

Homework:



Do Now:



Complete the remaining questions from the Monohybrid Crosses
Worksheet
Also, read pgs 267-273 and complete the “Reviewing Mendel’s 4
Principles of Genetic Inheritance” guide. Additionally, review key
vocabulary that we have gone over in class and be sure to have the
terms explained in your notebook.
Get a clicker and answer the questions on the following slides
You will need the Making Babies Analysis Questions
Today’s Objectives:


Use Mendel’s Principle of Segregation to explain: How can children show
traits that their parents don’t have?
Use Punnett Squares to solve monohybrid crosses
Do Now: Which of the following terms applies to traits,
such as eye color, that are controlled by more than one gene?
1.
2.
3.
4.
Codominant
Polygenic
Recessive
Dominant
90%
5%
1
0%
2
3
5%
4
Vocabulary Review
Pass Making Babies to the left!
DO NOW: Does this picture show GENOTYPES or
PHENOTYPES? “Click” your answer…
A.
B.
Genotypes
Phenotypes
76%
24%
A.
B.
Objectives for Class:
• Differentiate between genotypes and phenotypes
Vocabulary Review

Genotype:


Phenotype:


genetic make-up/combination of
alleles (Ex: AA, Aa, or aa)
The traits that an organism has (Ex:
purple flowers or white flowers)
Trait:

a specific characteristic that varies
between individuals (Ex: flower
color)
Objectives for Class:
• Differentiate between genotypes and phenotypes
Vocabulary Review

Fill in the blanks…
What is the phenotype?
What is the phenotype?
What is the genotype?

Which allele is dominant? Recessive? How do you know?
 Purple (A) = Dominant
 White (a) = Recessive
Objectives for Class:
• Differentiate between genotypes and phenotypes
New(ish) Vocabulary

Fertilization:
 the
joining of two gametes in
sexual reproduction

Zygote:
a
fertilized egg cell that will
grow and develop into an
offspring
A human zygote, like most other human cells, contains 46 chromosomes.
How many chromosomes does the a zygote receive from the mother?
1.
2.
3.
4.
12
23
46
92
100%
0%
1
0%
2
3
0%
4
In the diagram below, which process is
fertilization?
1.
2.
Process A
Process B
95%
5%
1
2
Monohybrid Punnett Square Practice
In guinea pigs, rough coat (R) is dominant over smooth coat (r). A
heterozygous guinea pig is mated with another heterozygous pig.
What percentage of the next generation will have smooth coat?
1.
2.
3.
4.
100%
50%
25%
75%
100%
0%
1
0%
2
0%
3
4
Introduction to Mendelian Genetics
Some background on Mendel and what
he did to advance genetics
You Don’t need to write this down:


Gregor Mendel studied
genetics by doing experiments
with pea plants.
He started with true-breeding
plants, which he knew were
homozygous for their traits.
Objectives for Class:
• Use Mendel’s Principle of Segregation to explain: How can children show traits that their parents don’t have?
• Use Punnett Squares to solve monohybrid crosses
Some background on Mendel and what
he did to advance genetics
You don’t need to write this down:





Gregor Mendel studied genetics by doing
experiments with pea plants.
He started with true-breeding plants, which
he knew were homozygous for their traits.
When he cross-bred these plants, he found
that one phenotype was dominant over the
other.
But when he cross-bred the offspring, the
recessive phenotype reappeared!
How can we explain this??
Objectives for Class:
• Use Mendel’s Principle of Segregation to explain: How can children show traits that their parents don’t have?
• Use Punnett Squares to solve monohybrid crosses
CW/ HW Monohybrid Crosses


Complete Question 1 (you will need to reference a
book
In sheep, the allele for black wool (a) is recessive
and the allele for white wool (A) is dominant.
Imagine that two white sheep that are
heterozygous mate with each other to produce
lambs.
 Trace
the alleles for each parent through diagrams of
Meiosis. Show the positions of the alleles on the
chromosomes at: Metaphase I, Metaphase II, and at
the end of meiosis. (In other words, draw the
chromosomes & the alleles!)
Review Principle of Segregation
Mendel’s Discoveries: Principle of Segregation

Alleles segregate (separate) during meiosis
so each gamete gets one allele
a
a
a
aA
Two choices for gametes:
A
A or a
A
A
Volunteer to Draw Punnett Square?

1c
 Draw
a Punnett Square showing the possible results of
2 heterozygous white sheep mating
Principle of Segregation
(continued…)


This explains why the
recessive trait
reappears in the F2
generation…
In ¼ of the offspring.
Source of
Gametes
Review: Principle of Segregation and Meiosis
AA
Possible
Haploid
Gametes
Original Diploid Cells
aa
Segregation
A
A
a
a
Fertilization
Aa
Aa
Aa
Possible Diploid Zygotes
Aa
CW/ HW Monohybrid Crosses

Complete Questions 2 – 4
Bio 9B: Monday, 3.28.11
Title: Dihybrid Crosses and Mendel’s Principle of Independent Assortment

Homework:
 Complete
the remaining questions from the Dihybrid Crosses
Worksheet

Do Now:
 What

are Mendel’s 4 Principles of Genetic Inheritance?
Today’s Objectives:


Use Punnett Squares to solve dihybrid crosses
Use Mendel’s Principle of Independent Assortment to explain how genetic
variation is created in individuals.
AGENDA
Pass Back Work
•Review HW
• Review Mendel’s 4 Principles of Inheritance
• Principle of Independent Assortment and DiHybrid Crosses
•
Question 2 (d): What is the probability of
purple flowers?
1.
2.
3.
4.
25%
50%
75%
0%
79%
21%
0%
1
0%
2
3
4
Question 3 (C): If Ben and Jaelene has a child, what
is the probability s(he) will have attached earlobes?
1.
2.
3.
4.
25%
50%
75%
0%
58%
32%
11%
0%
1
2
3
4
Question 4 (b): A cross between a cow and a bull that both have red
and white spots. What are the probabilities of a red calf?
1.
2.
3.
4.
25%
50%
75%
0%
74%
21%
5%
1
2
3
0%
4
Review Mendel’s Principles of Inheritance

Genes in Pairs:
 Traits
are controlled by genes that occur with two
different forms (alleles)

Principle of Dominance:
 Some

alleles are dominant and others are recessive
Principle of Segregation:
 The
two alleles for a gene segregate (separate) during
meiosis so each gamete gets one allele

Principle of Independent Assortment (new):
 Alleles
for different genes separate independently
during meiosis.
What is one difference between these two cells?
Cell 2
Cell 1
a
a A
A
b
b
A
a
a
B


A
B
Which chromosome is homologous to this one?
If we looked at human cells, how many pairs of
homologous chromosomes would they contain?
 Answer:
23 pairs (22 pairs plus the sex chromosomes)
A a
A
a
A a
A
a
or…
B
B
b
b
b
b
A
A
a
b
a
B B
B
b
B
A
a
A
b
Four
different possible
gametes:
B
b
AB
ab
Ab
aB
a
B
Mendel’s Discoveries:
Principle of Independent Assortment
 Alleles
for different genes separate independently
during meiosis.
 In
other words: If a gamete gets A or a, this doesn’t effect
whether it gets B or b. Any combo is possible:
Parent:
AaBb
Possible gametes:
AB
Ab
aB
ab
 This
creates genetic diversity between gametes, and
therefore a greater diversity of offspring.
Objectives for Class:
•Use Punnett Squares to solve dihybrid crosses
•Use Mendel’s Principle of Independent Assortment to explain how genetic variation is created in individuals.
Example: Dihybrid Cross
(only write what’s in purple)
Unattached earlobe (E) is dominant over attached earlobe (e)
Black hair (B) is dominant over blond hair (b)
 Two parents are heterozygous for both traits:
(1) Write the parent genotypes:
EeBb x EeBb
(2) What possible gametes can they each make?
EeBb
EB
Eb
eB
eb
Unattached w/ Black hair = 9/16
Unattached w/ Blond hair = 3/16
Attached w/ Black hair = 3/16
Attached w/ Blond hair = 1/16
(3) Write the gametes along the left side and top of
a BIG Punnett Square (4 x 4)
EB
Eb
eB
eb
EB EEBB
EEBb
EeBB
EeBb
Eb
EEBb
EEbb
EeBb
Eebb
eB
EeBB
EeBb
eeBB
eeBb
eb
EeBb
Eebb
eeBb
eebb
(4) Use the Punnett Square to calculate probabilities!
What is the probability of having a baby with
attached earlobes and black hair?
1.
2.
3.
4.
1/16
8/16
3/16
12/16
5
0%
0%
0%
0%
0
1
2
3
4
Complete Dihybrid Worksheet

Questions 1-2
example: dihybrid cross
Bio 9B: Tuesday, 3.29.11
Title: Genetic Inheritance & Variation -
Mendel’s Principle of Independent
Assortment

Homework:


Do Now:


Today’s Objectives:
Use Punnett Squares to solve dihybrid crosses
 Use Mendel’s Principle of Independent Assortment to explain how
genetic variation is created in individuals.

Did you complete the DiHybrid HW
1.
2.
Yes
No
5
0%
0%
0
1
2
1b. Suzy’s genotype is…?
5
1.
2.
3.
4.
Rr
Ry
RrYy
RRyy
0%
0%
0%
0%
0
1
2
3
4
1b. Suzy’s possible gametes are:
5
1.
2.
3.
4.
RR, YY, rr, yy
RY, Ry, rY, ry
RY, RY, ry, ry
R, Y, r, y
0%
0%
0%
0%
0
1
2
3
4
1d. The probability of round, green seeds is:
5
1.
2.
3.
4.
1 out of 4
3 out of 4
3 out of 16
9 out of 16
0%
0%
0%
0%
0
1
2
3
4
2. Rakim’s phenotype is (you will need to think about
this one!)
5
1.
2.
3.
4.
LlBb
LbLb
Flat chin, bent pinkies
Cleft chin, bent pinkies
0%
0%
0%
0%
0
1
2
3
4
2. Rakim’s genotype is:
5
1.
2.
3.
4.
LlBb
LbLb
Bb
LB
0%
0%
0%
0%
0
1
2
3
4
2. Rakim and Jennifer could both make which gametes?
5
1.
2.
3.
4.
Ll, Bb, ll, bb
LB, Lb, lB, lb
L, B, l, b
L or B
0%
0%
0%
0%
0
1
2
3
4
2. What is the probability that their child will have a cleft chin
and bent pinkies?
1.
2.
3.
4.
1 out of 4
1 out of 16
3 out of 4
9 out of 16
5
0%
0
1
0%
2
0%
3
0%
4
2. What is the probability that their child will have a flat chin
and straight pinkies?
5
1.
2.
3.
4.
1 out of 4
1 out of 16
3 out of 4
9 out of 16
0%
0%
0%
0%
0
1
2
3
4
3. What is Charlie’s genotype?
5
1.
2.
3.
4.
LLBB
LlBb
Llbb
llbb
0%
0%
0%
0%
0
1
2
3
4
3. Why is the Punnett Square only 1 by 4?
5
1.
2.
3.
4.
Because Jennifer and
Charlie only had 1 child.
Because Charlie has a
genetic mutation.
Because Charlie can only
make one type of
gamete.
Because Charlie doesn’t
have very much sperm.
0%
1
0
0%
2
0%
3
0%
4
3. What is the probability of a child with a flat chin and bent
pinkies?
5
1.
2.
3.
4.
1 out of
2 out of
3 out of
1 out of
4
4
4
16
0%
1
0
0%
2
0%
3
0%
4
Today’s Classwork

Practice Test
 Work
on your own or quietly with your table partner
 If you finish at least 10 questions in class with GOOD
explanation, you get a treat
 Earn more points for staying focused (and lose them for
distracting yourself or others)
 Please, I want to award points! Do your work!
 This will prepare you for the test we’ll have next
TUESDAY and will tell me what you still don’t
understand.
Bio 9C: Tuesday, 3.29.11
Title: Case Study: Albinism in the Bowman Family


Homework: None (or, if you didn’t finish the Genetics
Practice test, finish it!)
Silent Do Now: (in NB w/ title and date)
 Brainstorm
what you know and what questions you have
about albinism (this refers to people who are albino).

Today’s Objectives:

Analyze a family’s genetic traits in order to…
Construct a pedigree diagram
 Determine if a trait is dominant, recessive, or codominant

The Bowman Family (8 years ago)
The Bowman Family (more recent)
A Pedigree Diagram
Bio 9B: Wednesday, 3.30.11
Title: Case Study: Albinism in the Bowman Family – Day 2

Homework:
Complete through question 4 (this includes the pedigree, the
column for albinism and the questions associated with albinism).
 The project is due at the start end of the first half of the double
block tomorrow.


Silent Do Now: (in NB w/ title and date)


What questions still remain about albinism?
Today’s Objectives:

Analyze a family’s genetic traits in order to…


Construct a pedigree diagram
Determine if a trait is dominant, recessive, or codominant
Guidelines for working today:



Work alone to write your Background Info
paragraph
You may choose to work with one partner after
that. No groups bigger than 2!
You must ask permission to work at a back table.
Some people will work at the front desks.
A Pedigree Diagram
Bio 9B: Wednesday, 3.31.11
Title: Case Study: Albinism in the Bowman Family – Day 3

Homework:


Silent Do Now: (be honest here… )




Study for the Test!
On the front of Albinism Case Study, if you were able to identify the
genotypes for albinism for the members of the Bowman Family, then put
the letter “F” on the front of your case study.
If you struggled with this task, then put the letter “S” on the front of the
packet
If you did not attempt it, put the letter “A” on the front of the paper
Today’s Objectives:

Analyze a family’s genetic traits in order to…


Construct a pedigree diagram
Determine if a trait is dominant, recessive, or codominant
Completing the Bowman Pedigree
Block One
Question 5:
 Dark brown hair (D) is dominant over light brown hair (d).
Blue eyes (e) are recessive, so anyone with another color has
at least one dominant allele (E).



In the table on page 4, fill in the final column of genotypes for hair color and
eye color for all family members except those with albinism. (Hint: start with
Peter! Then figure out the parents, and then fill in everyone else.)
Make a Punnett square showing predicted ratios of genotypes and phenotypes
for hair and eye color in the Bowman children, based on their parents’
genotypes.
How closely do the actual numbers of children match these predictions?
Question 6:
nd Bowman child) is married to Alysia. Alysia is
 Michael (the 2
of Chinese descent, so she has black hair and dark brown
eyes. They do not have any children yet.
Genetics Test Review
Block Two

5 Minutes Individual/ Silent Work
Complete Part I of the Review Packet
 When completed, look over the vocab in Part II and the
practice problems in Part III and Part IV.

If you feel confident with your ability to complete ALL of the
problems, then put the letter “C” on the front of your review
packet
 If you feel confident with all of the problems except for the
Dihybrid cross problems, then put the letter “D” on the front of
your review packet
 If you feel confident with the vocab, but not the Monohybrid and
Dihybrid problems, the put the letter “M” on the front of the
packet
 If you don’t feel confident with most of the content of the review
packet, the put the letter “A” on the front of the packet

Genetics Review
Block Two




Divide into sections of the class based on letters.
M’s and D’s in the front seats
C’s at the back tables
A’s at the front tables