Bio 9C: Monday, 3.21.11Title: Introduction to Genetic Inheritance and Variation

Homework: Finish Drawing your baby and 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

Review Karyotyping Part II Introduction to new Genetics Terms (15 min) Makin’ Babies Activity

Explanation (5 minutes) Activity (25 minutes)

Post picture of the Baby on the front board Introduction to Punnett Squares (15 Min) Making Babies Probability w/ clickers (15 min)Making Babies Analysis Questions (20 min)

Agenda

Karyotyping Activity – Part II ReviewNondisjunction Videos

MENDELIAN GENETICS:THE STUDY OF GENETIC INHERITANCE PATTERNSBiology 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!

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

Mendelian Genetics and Probability

Objectives for Class:• Experiment with probability to see the diversity of offspring that can be made through sexual

reproduction

Evidence:True-breeding yellow x True-breeding green

(YY) (yy) All yellow offspring (Yy)

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”

Mendelian Genetics and Probability

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 XTails = Recessive and Y

Example: Face shape = R, so heads=R and tails = rWrite the combination of the alleles in the box next to the trait. This is the Genotype for each trait

Step 2: Phenotype chartDetermine the Phenotype based on the Genotype from page 1Example: 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

Bio 9B: Tuesday, 3.22.11Title:

Homework: Complete Making Babies Analysis Questions

Do Now: Take the clicker assigned to you and sign in:

Type: “channel - 0 - 2 - channel”

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

Your Clicker Number:Write it on the FRONT of your notebook

Clicker Number

Student Name

1 Christine 2 Alex3 Karen 4 Kendra5 Liliana 6 Maryem7 Joseph8 Jason 9 Obayanna 10 Garlyn11 Amando 12 Carla

Clicker Number

Student Name

13 Sophie14 Jonathan 15 Anthony 16 Brunyr 17 Crystal18 Rockens19 Marcus20 Julian 21 Marie 22 Jamesly23 Jhon May 24 Asarel 25 Amanjot

Introduction to Punnett Squares/ Monohybrid Crosses (15 Min)

Making Babies Probability w/ clickers (20 min) Making Babies Analysis Questions (15 min)

Agenda

Homozygous and Heterozygous Homozygous: Two of the same allele

for a particular trait are presentEx: RR (homozygous dominant) = Round

FaceEx: rr (homozygous recessive)= Square Face

Heterozygous: Two different alleles for a particular trait are presentEx: Rr = Round Face

More Genetics Vocabulary

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 Rrhalf of the sperm got each

allele½ of Mom’s eggs got the R allele

½ of Mom’s eggs got the r allele

R

r

rRRR

rr

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

rRRR

rr

Rr

Rr

Now let’s make predictions for the sex of the baby (boy or girl?)

Mother’s genotype: Father’s genotype: Make a Punnett Square and fill it in

Chances of girl (XX)

= ½ or 50%

Chances of boy (XY)

= ½ or 50%

X

YX

X

XX

XY

XY

XX

XXXY

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

Now let’s see if the class’s babies match our predicted probabilities!

TraitEXPECTED Ratio

PERCENT of Babies with Dominant Phenotype

PERCENT of Babies with Recessive Phenotype

Face Shape 75%, 25%

Cleft Chin 75%, 25%Widow’s Peak 75%, 25%

Earlobes 75%, 25%Gender 50%, 50%

Phenotype Class Results:What is the face shape of your baby?

1 2

5%

95%1. Round (dominant)

2. Square (recessive)

Objectives for Class:• Experiment with probability to see the diversity of offspring that can be made through sexual

reproduction

1 2

18%

82%

Phenotype Class Results:Does your baby have a cleft chin? 1. No, it’s absent

(dominant)2. Yes, it’s present

(recessive)

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

48%

52%1. Yes, it’s present

(dominant)2. No, it’s absent

(recessive)

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

43%

57%1. Unattached (dominant)

2. Attached (recessive)

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

45%

55%1. Girl (XX)2. Boy (XY)

Objectives for Class:• Experiment with probability to see the diversity of offspring that can be made through sexual

reproduction

Take out the Making Babies packet and turn to the very back page

We will use clickers to collect data for Analysis Question #5

Now let’s see if the class’s babies match our predicted probabilities!

TraitEXPECTED Ratio

PERCENT of Babies with Dominant Phenotype

PERCENT of Babies with Recessive Phenotype

Face Shape 75%, 25%

Cleft Chin 75%, 25%Widow’s Peak 75%, 25%

Earlobes 75%, 25%Gender 50%, 50%

Making Babies – Analysis Questions Complete Making Babies Analysis

questions on a separate piece of paper This is HW due tomorrow!

Bio 9C: Wednesday, 3.23.11Title: No Class – Half Day

Homework:

Do Now:

Today’s Objectives:

Your Clicker Number:Write it on the FRONT of your notebook

Clicker Number

Student Name

1 Christine 2 Alex3 Karen 4 Kendra5 Liliana 6 Maryem7 Joseph8 Jason 9 Obayanna 10 Garlyn11 Amando 12 Carla

Clicker Number

Student Name

13 Sophie14 Jonathan 15 Anthony 16 Brunyr 17 Crystal18 Rockens19 Marcus20 Julian 21 Marie 22 Jamesly23 Jhon May 24 Asarel 25 Amanjot

Bio 9C: Thursday, 3.24.11Title: Genetic Inheritance & Variation - Mendel’s Principle of Segregation

Homework: Complete the remaining questions from the Monohybrid Crosses

Worksheet Also, read pgs 265-273 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.

Do Now: 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

0%5%

14%

81%1. Codominant2. Polygenic 3. Recessive4. Dominant

Pass Making Babies to the left!

Vocabulary Review

DO NOW: Does this picture show GENOTYPES or PHENOTYPES? “Click” your answer…

A. B.

80%

20%

A. GenotypesB. Phenotypes

Objectives for Class:• Differentiate between genotypes and phenotypes

Vocabulary Review Genotype:

genetic make-up/combination of alleles (Ex: AA, Aa, or aa)

Phenotype: 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…

Which allele is dominant? Recessive? How do you know? Purple (A) = Dominant White (a) = Recessive

What is the phenotype?

What is the phenotype?

What is the genotype?

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

5% 5%0%

90%1. 122. 233. 464. 92

In the diagram below, which process is fertilization?

1 2

20%

80%1. Process A2. Process B

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. 100%2. 50%3. 25%4. 75%

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

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

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??

Some background on Mendel and what he did to advance genetics

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!)

You need to get my approval before moving on to questions 2, 3, and 4!!!

Review Principle of Segregation

                              

Mendel’s Discoveries: Principle of Segregation Alleles segregate (separate)

during meiosis so each gamete gets one allele

a a A A

a Aa A

Two choices for gametes:A or a

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

AaAaAaAa

A aA a

aaOriginal Diploid

Cells

Segregation

Fertilization

Possible Haploid

Gametes

Possible Diploid Zygotes

CW/ HW Monohybrid Crosses Complete Questions 2 – 4

Question 2 (d): What is the probability of purple flowers?

1. 25%2. 50%3. 75%4. 0%

Question 3 (C): If Ben and Jaelene has a child, what is the probability s(he) will have attached earlobes?

1 2 3 4

0% 0%0%0%

1. 25%2. 50%3. 75%4. 0%

0

5

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

0% 0%0%0%

1. 25%2. 50%3. 75%4. 0%

0

5

Reading to review and preview concepts

Read pgs 265-273 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.

Bio 9C: Friday, 3.25.11Title: 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 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

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?

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)

aaA A

b b

BB

a a A A

Cell 1 Cell 2

                              

AB

A A aa

b bBB

A A aa

b b BB

AB

ab

ab

or…

aB

Ab

aB

Ab

Four different possible gametes:AB ab Ab aB

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.

Mendel’s Discoveries: Principle of Independent Assortment

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?

E e B bEB

Eb

eB

eb

Unattached w/ Black hair = Unattached w/ Blond hair =

(3) Write the gametes along the left side and top of a BIG Punnett Square (4 x 4)

(4) Use the Punnett Square to calculate probabilities!

EB

Eb

eB

eb

EB Eb eB eb

EEBb

EeBB

EeBb

EEBB

Eebb

EeBb

EEbb

EEBb EeBB

EeBb

eeBB

eeBb eebb

eeBb

Eebb

EeBb

Attached w/ Black hair = Attached w/ Blond hair = 1/16

9/163/16

3/16

What is the probability of having a baby with attached earlobes and black hair?

1 2 3 4

0% 0%0%0%

1. 1/162. 8/163. 3/164. 12/16

0

5

Complete Dihybrid Worksheet Questions 1-2

example: dihybrid cross

Bio 9C: Monday, 3.28.11Title: 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

0%0%

1. Yes2. No

0

5

1b. Suzy’s genotype is…?

1 2 3 4

0% 0%

96%

4%

1. Rr2. Ry3. RrYy4. RRyy

1b. Suzy’s possible gametes are:

1 2 3 4

0% 0%4%

96%1. RR, YY, rr, yy2. RY, Ry, rY, ry3. RY, RY, ry, ry4. R, Y, r, y

1d. The probability of round, green seeds is:

1 2 3 4

10%14%

76%

0%

1. 1 out of 42. 3 out of 43. 3 out of 164. 9 out of 16

2. Rakim’s genotype is:

1 2 3 4

91%

0%0%9%

1. LlBb2. LbLb3. Bb4. LB

2. Rakim’s phenotype is (you will need to think about this one!)

1 2 3 4

0%

76%

24%

0%

1. LlBb2. LbLb3. Flat chin, bent

pinkies4. Cleft chin, bent

pinkies

2. Rakim and Jennifer could both make which gametes?

1 2 3 4

5%0%

5%

90%1. Ll, Bb, ll, bb2. LB, Lb, lB, lb3. L, B, l, b4. L or B

2. What is the probability that their child will have a cleft chin and bent pinkies?

1 2 3 4

5%

76%

10%10%

1. 1 out of 42. 1 out of 163. 3 out of 44. 9 out of 16

2. What is the probability that their child will have a flat chin and straight pinkies?

1 2 3 4

9%5%

9%

77%1. 1 out of 42. 1 out of 163. 3 out of 44. 9 out of 16

3. What is Charlie’s genotype?

1 2 3 4

0%

100%

0%0%

1. LLBB2. LlBb3. Llbb4. llbb

3. Why is the Punnett Square only 1 by 4?

1 2 3 4

10%5%

86%

0%

1. Because Jennifer and Charlie only had 1 child.

2. Because Charlie has a genetic mutation.

3. Because Charlie can only make one type of gamete.

4. Because Charlie doesn’t have very much sperm.

3. What is the probability of a child with a flat chin and bent pinkies?

1 2 3 4

89%

5%5%0%

1. 1 out of 42. 2 out of 43. 3 out of 44. 1 out of 16

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, 3.29.11Title: 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

Do you feel like you confidently answered the “challenge” questions in Part III of the Review Packet?

1 2 3

0% 0%0%

1. Yes2. Somewhat3. No

0

5

The Bowman Family (8 years ago)

The Bowman Family (more recent)

A Pedigree Diagram

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.

Bio 9C: Wednesday, 3.30.11Title: Case Study: Albinism in the Bowman Family - 2

Homework:

Silent Do Now: (in NB w/ title and date)

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

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

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

0% 0%0%0%

1. 25%2. 50%3. 75%4. 100% 0

5

Why are the actual percents a bit different?