Bio 9C: Thursday, 3.17.11
Title: Introduction to Genetic Inheritance and Variation

Homework:
Double Block
Give me your Notebooks at the end of class (After the Do Now
and the Genetics Overview)!!!!
 Finish drawing your baby and answering Analysis questions 1-3 on
a separate sheet of paper to be handed in!


Do Now:


How can an error in meiosis result in abnormal chromosome
numbers in people? Nondisjunction Videos
Today’s Objectives:


Describe the two ways meiosis creates genetic diversity between gametes
Experiment with probability to see the diversity of offspring that can be
made through sexual reproduction
Karyotyping Activity – Part II Review
Nondisjunction Videos
MENDELIAN GENETICS &
GENETIC INHERITANCE
Biology 9
Moretti and Dickson
Genetics Overview


The study of gene inheritance and variation
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
Mendelian Genetics and Probability

New Vocabulary:
Dominant and Recessive
 Genotypes and Phenotypes
 Homozygous and Heterozygous

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:

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 organism
 The combination of alleles
 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
Mendelian Genetics and Probability

New Vocabulary:
 Homozygous
and Heterozygous
 Homozygous:
Two of the same allele for a
particular trait are present
 Ex:
RR = Round Face
 Ex: rr = 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
“Makin’ Babies”: Mendelian Genetics & Probability





Use the “Genotype Data Table” to 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
For 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
Then, go to the Phenotype chart
 Determine the Phenotype based on the Genotype from page 1
 For example: if you flipped two RR for face shape, the phenotype would be Round
After all of the Phenotypes are determined, draw your baby by using the traits from
the Phenotype chart
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Bio 9C: Wednesday, 3.24.10
Title: Genetic Inheritance and Variation

Homework:


Complete the monohybrid worksheet practice problems
Do Now:
Learning how to use the “CLICKERS”
 On the next slide…


Today’s Objectives:




Differentiate between genotypes and phenotypes
Experiment with probability to see the diversity of offspring that can be
made through sexual reproduction
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
Wednesday, 3.24.10: Block 1
Objectives:
•
•
Differentiate between genotypes and phenotypes
Experiment with probability to see the diversity of
offspring that can be made through sexual
reproduction
Learning how to use the “Clickers”

What are they?


Audience response tools that allow you to
enter your response/ answer by “clicking”
the handheld response card (sort of like
Jeopardy).
Why are they cool?
Everyone can participate in class!
 You can answer questions from class without
waiting to be called upon!
 In seconds, we can determine how many
people really understand what we are doing
and adjust accordingly to meet the needs of
the class!

Learning how to use the “Clickers”

How do they work?




Each of you will get a clicker
assigned to you (based on your last
name position in the alphabet).
Every day you come to class, you will
take your Clicker from the Clicker
rack and sit down.
As I post slides that have questions
for you to answer, you will “click”
your answer on the handheld Clicker.
Your response goes right to the
computer where software records the
responses, tabulates the numbers of
responses, and creates graphs to
show how the class responds.
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
Beverly
Alain
Alejandra
Drishti
Derrell
Michael
Carl
Arielle
Rowan
Nehemie
Maddie
Aaliyah
Clicker
Number
13
14
15
16
17
18
19
20
21
22
23
Student Name
Yasmine
Jasmine
Erik
Kiraleah
Gustavo
Ashley
Milly
Martin
Rishab
Larissa
Hannah
Now…


Get your clicker
Once everyone has their clicker…
 Hold
down the Channel button for a few seconds
 Press ZERO and then TWO
 Press Channel again
(This will set your clicker to the proper channel)
DO NOW: Does this picture show GENOTYPES or
PHENOTYPES? “Click” your answer…
A.
B.
Genotypes
Phenotypes
83%
17%
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
“Makin’ Babies”: Review and Analysis (w/ the Clickers)


Now we will use the Clickers to collect the Class Results for
question 4.
To do this, enter in your baby’s phenotype for each of the
following traits:







Face Shape
Cleft Chin
Widow’s Peak
Earlobes
Gender
As we address each trait, write the percentages for each
phenotype in the Class Results chart.
Use this data to complete analysis question #4.
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 face shape of your baby?
1.
2.
Round (dominant)
Square (recessive)
83%
17%
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)
74%
26%
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)
57%
43%
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)
78%
22%
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)
52%
48%
1
2
Objectives for Class:
• Experiment with probability to see the diversity of offspring that can be made through sexual reproduction
Complete the Analysis Questions for
the “Makin’ Babies” Activity

Please complete the remaining questions…
Wednesday, 3.24.10: Block 2
Genetic Inheritance & Variation - Mendel’s
Principle of Segregation
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
87%
9%
4%
1
0%
2
3
4
Vocabulary Review

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
52%
48%
1
2
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
Mendel’s Discoveries


Principle of Segregation
Principle of Independent Assortment
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
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
Principle of Segregation
(continued…)


This explains why the
recessive trait
reappears in the F2
generation…
In ¼ of the offspring.
Source of
Gametes
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
Bio 9C: Thursday, 3.23.10
Title: Genetic Inheritance & Variation – “Counting Corn” Day 1

Homework:


Complete the calculations for the Part B and C analysis. Complete
conclusion questions 1 and 2. (note: different than assignment
sheet). Due Monday
Do Now:
Homework Review: We need 3 volunteers to put problems 2, 3,
and 4 on the side board
 Everyone else is “clicking” their answers in


Today’s Objectives:



Use Punnett Squares to solve monohybrid crosses
Use Punnett Squares to solve dihybrid crosses
Use Mendel’s Principle of Independent Assortment to explain how genetic variation
is created in individuals.
Question 2 (d): What is the probability of
purple flowers?
1.
2.
3.
4.
25%
50%
75%
0%
75%
15%
10%
0%
1
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%
87%
13%
0%
1
2
3
0%
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%
83%
13%
0%
1
2
3
4%
4
Review: Principle of Segregation and Meiosis
Diploid Cells
AA
Possible
Haploid
Gametes
aa
Segregation
A
A
a
a
Fertilization
Aa
Aa
Aa
Possible Diploid Zygotes
Aa
“Counting Corn”: Genetic Crosses in Organisms

Part A: Developing Your Hypothesis


Part B: Investigating an actual F2


Use your knowledge of probability and inheritance to develop a
hypothesis for the percentages of two different phenotypes found in
the F2 generation of corn offspring (seeds).
Test your hypothesis with an ear of corn. The kernels on these ears of
corn are the F2 offspring from a cross that began with two parental
varieties of corn with contrasting phenotypes (one yellow one purple).
Part C: Investigating Two Traits

For this section you will see what happens when you look at the
inheritance of two separate traits? Mendel studied this by looking at
seed color AND seed shape in pea plants – and that’s what you will do
next, with an ear of corn.
Objectives for Class:
•Use Punnett Squares to solve monohybrid crosses
•Use Punnett Squares to solve dihybrid crosses
•Use Mendel’s Principle of Independent Assortment to explain how genetic variation is created in individuals.
“Counting Corn”: Genetic Crosses in Organisms

Part A Procedure: Examine the pictures for corn kernel color and answer questions in
your notebooks
Parent (P1)
Parent (P2)
X
First Generation (F1)
X
Second Generation (F2)
“Counting Corn”: Genetic Crosses in Organisms

Part A: Developing Your Hypothesis


Part B: Investigating an actual F2


Use your knowledge of probability and inheritance to develop a
hypothesis for the percentages of two different phenotypes found in
the F2 generation of corn offspring (seeds).
Test your hypothesis with an ear of corn. The kernels on these ears of
corn are the F2 offspring from a cross that began with two parental
varieties of corn with contrasting phenotypes (one yellow one purple).
Part C: Investigating Two Traits

For this section you will see what happens when you look at the
inheritance of two separate traits? Mendel studied this by looking at
seed color AND seed shape in pea plants – and that’s what you will do
next, with an ear of corn.
Objectives for Class:
•Use Punnett Squares to solve monohybrid crosses
•Use Punnett Squares to solve dihybrid crosses
•Use Mendel’s Principle of Independent Assortment to explain how genetic variation is created in individuals.
Bio 9C: Friday, 3.26.10
Title: Genetic Inheritance & Variation – “Counting Corn” Day 2

Homework:
 Complete
the calculations for the Part B and C analysis.
Complete conclusion questions 1 and 2. (note: different than
assignment sheet). Due Monday

Do Now:
 Get

an ear of corn and begin counting the kernels for Part B
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.

“Counting Corn”: Genetic Crosses in Organisms

Part B: Investigating an actual F2

Test your hypothesis with an ear of corn. The kernels on these ears of corn are the F2
offspring from a cross that began with two parental varieties of corn with contrasting
phenotypes (one yellow one purple).
Phenotype
Your Group’s Counts
Yellow
Total Kernels ____________
Purple
Total Kernels ____________
Total # of
Kernels Counted
Class Count Totals
“Counting Corn”: Genetic Crosses in Organisms

Part A: Developing Your Hypothesis


Part B: Investigating an actual F2


Use your knowledge of probability and inheritance to develop a
hypothesis for the percentages of two different phenotypes found in
the F2 generation of corn offspring (seeds).
Test your hypothesis with an ear of corn. The kernels on these ears of
corn are the F2 offspring from a cross that began with two parental
varieties of corn with contrasting phenotypes (one yellow one purple).
Part C: Investigating Two Traits

For this section you will see what happens when you look at the
inheritance of two separate traits? Mendel studied this by looking at
seed color AND seed shape in pea plants – and that’s what you will do
next, with an ear of corn.
Objectives for Class:
•Use Punnett Squares to solve monohybrid crosses
•Use Punnett Squares to solve dihybrid crosses
•Use Mendel’s Principle of Independent Assortment to explain how genetic variation is created in individuals.
Bio 9C: Monday, 3.29.10
Title: Genetic Inheritance & Variation – Mendel’s Principle of Independent
Assortment

Homework:
Brainstorm the background information in your notebook (clearly
label this!). Type the background information section based on
your brainstorm (don’t forget to make connections between the
points).
 Completed typed lab reports are Due Thursday!


Do Now:


On the next slide…
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.
Answering Corn Lab Questions



Why Part A?
How does Part A connect to Part B?
How does having 2 traits change things?
Bio 9C: Tuesday, 3.31.10
Title: Genetic Inheritance & Variation -
Mendel’s Principle of Independent
Assortment

Homework:
Finish the Dihybrid Crosses Worksheet if you didn’t finish it in class.
 Revise or complete Steps 5-9 of Part C on the Corn Lab if you
haven’t already, or if you can do a better job after today’s lesson
on dihybrid crosses. Refer to the Dihybrid Crosses Worksheet for
help if you need it.


Do Now:


On the next slide…
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.
DO NOW: In sheep, the allele for white wool is dominant (W)
and the allele for black wool (w) is recessive. A farmer has
mated two sheep for a few years and produced six offspring : 4
white and 2 black. One of the sheep has black wool and the
other has white wool. Which of the following is likely the
genotypes of the parent sheep?
55%
1.
2.
3.
4.
WW and Ww
WW and ww
Ww and Ww
Ww and ww
20%
15%
10%
1
2
3
4
Quick Review from Monday

What is one difference between these two cells?
Cell 2
Cell 1
a
a A
b
A
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 segregate 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
Example: Dihybrid Cross
(only write what’s in purple)
Unattached earlobe (E) is dominant over attached (e)
Black hair (B) is dominant over blond hair (b)
 What are the potential phenotypic combinations?

Two parents are heterozygous for both traits:
(1) Write the parent genotypes:
(2) What gametes can they make?
Example: Dihybrid Cross continued
(3) Write the gametes along the sides of a BIG
Punnett Square (4 boxes x 4 boxes = 16 boxes)
(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
86%
14%
0%
1
0%
2
3
4
“Counting Corn”: Genetic Crosses in Organisms

Remainder of Class:
 Collect
and Review Class Data
 Setting up our Dihybrid cross for Part C of the corn lab/
finishing Part C
 Begin Dihybrid cross activity
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.
Bio 9C: Thursday, 4.1.10
Title: Genetic Inheritance & Variation -
Mendel’s Principle of Independent
Assortment

Homework:
 Complete

Do Now:
 Very

the Mendelian Genetics Review packet
Quickly on the next slide…
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.

Q3 from HW: What is the probability that Charlie and
Jennifer’s child will have a flat chin and bent pinkies?
1.
2.
3.
4.
50%
25%
75%
0%
100%
0%
1
0%
2
3
0%
4
“Counting Corn”: Genetic Crosses in Organisms

Today in Class:
 Collect
and Review Class Data
 Setting up our Dihybrid cross for Part C of the corn lab/
Finishing Part C
 Begin Mendelian Genetics Review Activity
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.
Table 1: Part C Class Data
Group
1
2
3
4
5
6
7
8
9
10
11
12
% Yellow Corn
% Purple Corn
“Counting Corn”: Genetic Crosses in Organisms

Remainder of Class:
 Setting
up our Dihybrid cross for Part C of the corn
lab/ Finishing Part C
 Begin Mendelian Genetics Review Activity
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.
Bio 9C: Monday, 4.5.10
Title: Big Quiz Review Day – Genetics and Inheritance

Homework:
 Labs
are Due Wednesday at the start of class
 Study for the BIG Quiz on Friday

Do Now:
 On

the next slide…
Today’s Objectives:

Review Genetics Content for Wednesday’s BIG QUIZ (small test)
Do Now:
Data Analysis Practice
Take out a calculator.

Calculate the % of offspring with long wings. Show your work!

Calculate the % of offspring with vestigial wings. Show your work!

Do you think vestigial wings are dominant, recessive, or co-dominant? Why?

What are the genotypes of the two long-winged fruit flies that were crossed
(mated) in this example?
Do Now: Analyzing Genetic Data




% of Long Wings =
73 divided by 95 = 0.768 = 77% Long Wings
% of Vestigial Wings =
22 divided by 95 = 0.2316 = 23% Vestigial Wings
Vestigial Wings are…
Recessive because two parents with long wings had some
babies with vestigial wings. This means the parents carried a
copy of the vestigial allele but didn’t show it.
The two long-winged fruit fly parents are…
Heterozygous (Aa x Aa)
What percent of the wings would you
expect to be long?
1.
2.
3.
4.
25%
50%
75%
100%
100%
0%
1
0%
2
0%
3
4
Why are the actual percents a bit different?
Have you completed the Mendelian
Genetics Review Packet?
1.
2.
Yes
No
50%
1
50%
2
Do you feel like you confidently answered the
“challenge” questions in Part III of the Review Packet?
1.
2.
3.
Yes
Somewhat
No
55%
45%
0%
1
2
3
Big Quiz Review: Mendelian Genetics


Continue with the Mendelian Genetics Review
Packet.
If you feel like you have confidently answered all of
the questions, then complete an “extension” packet