Top Banner
Punnett Squares
26

Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Jan 04, 2016

Download

Documents

Heather Cole
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Punnett Squares

Page 2: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Wednesday!

Bell Ringer: Objective:• Predict the offspring of a

cross in a Punnett Square

Page 3: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

AGENDA1. Independent Reading

2. Notes on Punnett Squares

3. Practice Punnett Squares4. Exit Ticket

Page 4: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Essential Question

• What information do I need to know in order to set up a Punnett square?

Page 5: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Read

• Phenotypes and Genotypes 258-259• Stop when you reach “Dihybrid Crosses” on

page 259• Take Cornell Notes

Page 6: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

C.H.A.M.P.s

• Conversation: It is expected that you remain silent while you read

• Help: Raise your hand for help

• Activity: Reading on Punnet squares

• Movement: You should remain in your seat

• Participation: You are meeting expectations if you are working on your reading.

Page 7: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

C.H.A.M.P.s

• Conversation: It is expected that you remain silent while I lecture

• Help: Raise your hand for help

• Activity: Notes on Mendel

• Movement: You should remain in your seat while I am lecturing

• Participation: You are meeting expectations if you are quietly taking notes and asking questions.

Page 8: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

MAKING A CROSS for only a __________ trait =

____________________

A Punnett square for a MONOHYBRID CROSS looks like:

MONOHYBRID CROSSONE GENE

Page 9: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

PUNNETT SQUARESare used to show possible offspring

from a cross between 2 parents

_______________ go at top and on left side

Boxes show _______________________________

T T

T

t

possible offspring combinations

Parent alleles

Page 10: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

1. ___________ what _________________ are2. ________correct__________ square __________3. ______ possible_______________________4. ______ boxes with _____________________5. Determine ____________of_____________& ____________

STEPS FOR MAKING CROSSES

Figure out parent allelesChoose Punnett size

Put in parent gametesFill in offspring combinations probabilities phenotypes

genotypes

Page 11: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

IN PEA PLANTS

Tall is dominant over short TALL = ____

SHORT = ____T

tLET’S MAKE A CROSS!

PURE TALL PURE SHORTX

Page 12: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

PURE TALL parentWhat are the parent alleles?

T T

T T

HOMOZYGOUS

What gametes can it make?

Page 13: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

PURE SHORT parent What are the parent alleles?

t t

t t

HOMOZYGOUS

What gametes can it make?

Page 14: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

GENOTYPE _____ PHENOTYPE _______

_____ of the offspring

____ % ___/4 will be

_______

T T

t

t

T t T t

T t T t

Tt TALL

ALL

1004

TALL

Page 15: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Let’s Try Again!

Brown eyes is dominant over green eyes

BROWN EYES = ____GREEN EYES = ____

Bb

LET’S MAKE A CROSS!Heterozygous brown (mom) Heterozygous brown (dad)

Page 16: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Mom-Heterozygous BrownWhat are the parent alleles?

B b

B b

HETEROZYGOUS

What gametes can it make?

Page 17: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Dad-Heterozygous BrownWhat are the parent alleles?

B b

B b

HETEROZYGOUS

What gametes can it make?

Page 18: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Try the Cross!

B b

B

b

B B B b

B b b b

Page 19: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

_____

of the offspring ____ % ___/4will have _________

GENOTYPES _______ PHENOTYPES _______________

_______ _______________

_______ _______________

WHAT ARE THE POSSIBLE…

_____

of the offspring ____ % ___/4 will have _________

BbBB

253

75

13

brown eyes1

green eyes

bb Green eyes

Brown eyes

Brown eyes

Page 20: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

EXIT TICKET• Complete a punnett square. The mother is

heterozygous for brown hair and the father is homozygous dominant for brown hair.

Mother = Bb

Father = BB

B b

B

B

BB Bb

BB Bb

Genotype = 2/4 BB 2/4 Bb

Phenotype = 4/4 Brown hair

Page 21: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Bell Ringer:

B b

B

b

BB Bb

Bb bb

Genotype = ¼ BB 2/4 Bb

¼ bb

Phenotype = ¾ Brown eyes

¼ Green eyes

Page 22: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Review:

• Take out a sheet of paper • Follow along with the next few slides to

review

Page 23: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Homozygous or Heterozygous• Gg

• kk

• YY

• Aa

• Heterozygous

• Homozygous Recessive

• Homozygous Dominant

• Heterozygous

Page 24: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Genotype or Phenotype?

• Rhonda has brown hair• Rhonda is BB• Jeffrey is Tt• Jeffrey is tall• Robert is homozygous tall• Jasmine is heterozygous for her dimples

Page 25: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Critical Thinking1) Tracy’s mom has green eyes. Her dad’s eyes are

dark brown. Tracy and all her brothers and sisters have dark brown eyes. Which allele is recessive?

2) James has a dominant allele for hitch-hiker’s thumb (H) and a recessive allele for not having it (h). He is able to bend his thumb backwards. Is he homozygous or heterozygous?

Page 26: Punnett Squares. Wednesday! Bell Ringer:Objective: Predict the offspring of a cross in a Punnett Square.

Punnett Square Challenge

• Work with one partner to complete the Punnett Square Challenge

• Make sure to get a stamp where indicated.