
Epistasis Lesson
Presentation
•
Biology
•
10th - 12th Grade
•
Practice Problem
•
Hard
Standards-aligned
Brian Ackert
Used 8+ times
FREE Resource
21 Slides • 20 Questions
1
Epistasis Lesson
2
Learning Targets
I can explain the difference between epistasis dominant and epistasis recessive.
I can identify the 'appearance' of epistasis genotypes.
I can use punnett squares to predict the ratio of crosses involving epistasis dom/rec.
3
Before you begin...
Please have notebook paper, blank 16 box page, green allele sheet available.
4
5
Multiple Choice
______ is the genetic occurrence in which two genes interact. One gene may 'suppress' another gene.
Epigenetics
Epistasis
Genomics
Trasnsmutations
6
Multiple Select
Based on the introduction...this video is going to focus on..
Labrador Retrievers Coloration
Squash Coloration
Gerbils Coloration
Hamster Coloration
Zucchini Coloration
7
I might add...
Epistasis can also be thought of how one gene can 'turn off' another gene. We will learn how an epistasis gene can turn off the coloration gene that may be present in labs and squash plants. This causes labs to look yellow or squash to be white colored fruits.
8
9
Multiple Choice
Based on the presentation SQUASH, the epistasis gene is _________.
Dominant
Recessive
10
Multiple Select
So...B = Coloration Masked (white), b = Coloration gene 'unmasked'. A = Yellow and a = green coloration. Which genotypes below would be WHITE in coloration?
aaBb
AaBB
aabb
AAbb
Aabb
11
Since the 'B' gene masks the yellow/green gene, then...
aaBb and AaBB would BOTH be WHITE squash plants. The "B" turns off the coloration gene.
12
Multiple Select
So...B = Coloration Masked (white), b = Coloration gene 'unmasked'. A = Yellow and a = green coloration. Which genotypes below would be YELLOW in coloration?
aaBb
aabb
AaBB
AAbb
Aabb
13
Multiple Select
So...B = Coloration Masked (white), b = Coloration gene 'unmasked'. A = Yellow and a = green coloration. Which genotype(s) below would be GREEN in coloration?
aaBb
aabb
AaBB
AAbb
Aabb
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16
17
Multiple Choice
What is the color of the two parents? bbAa x BbAa
B = masking
b = No masking
A = yellow
a = green
Yellow x White
Yellow x Yellow
White x Yellow
Yellow x green
green x yellow
18
Multiple Choice
What will be the ration of WHITE: YELLOW: GREEN offspring?
8 W: 6 Y: 2 G
8 W: 2 Y: 6 G
8 W: 4 Y: 4 G
6 W: 6Y: 4 G
Some other ratio
19
How Mr. Ackert worked this one!.
Here is my answer key to the previous. 8 White, 6 Yellow and 2 White
20
Poll
Do you feel you understand the concept of Epistasis DOMINANT?
Yes, Iḿ ready to move on.
No, I need a bit of help.
21
If you need help...
Please ask Mr. Ackert before you move onto the next section. Thanks!
22
23
Please write these down:
E = Masking - OFF
e = Masking - ON (Yellow Coat)
B = Black coat
b = Chocolate Coat (brown)
24
Also know...the epistasis gene (ee) will NOT mask the nose and paw pad coloration.
25
Multiple Choice
A lab with the genotype of:
EeBb
would have a phenotype of...
Black fur / Black nose
Black fur / Chocolate nose
Yellow Fur / Black nose
Yellow Fur / Chocolate nose
Yellow fur / yellow nose
26
Multiple Choice
A lab with the genotype of:
eeBb
would have a phenotype of...
Black fur / Black nose
Black fur / Chocolate nose
Yellow Fur / Black nose
Yellow Fur / Chocolate nose
Yellow fur / yellow nose
27
Multiple Choice
A lab with the genotype of:
eebb
would have a phenotype of...
Black fur / Black nose
Black fur / Chocolate nose
Yellow Fur / Black nose
Yellow Fur / Chocolate nose
Yellow fur / yellow nose
28
Multiple Choice
A lab with the genotype of:
Eebb
would have a phenotype of...
Black fur / Black nose
Chocolate fur / Chocolate nose
Yellow Fur / Black nose
Yellow Fur / Chocolate nose
Yellow fur / yellow nose
29
Multiple Select
Which of these could be sold as a PUREBRED Labrador retrievers?
eebb
eeBB
EeBB
EEbb
eeBb
30
A dog MUST be homozygous for both epistasis AND coloration
EEBB, EEbb, eeBB, eebb
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34
Multiple Select
Which of these describe the two parents dogs of this cross?
Black Lab / Black Nose
Chocolate Lab / Chocolate Nose
Yellow Lab / Black Nose
Yellow Lab / Chocolate Nose
Both Dogs are yellow labs
35
Fill in the Blanks
How many of the 16 boxes represent a Black Lab Offspring?
Type answer...
36
Fill in the Blanks
How many of the 16 boxes represent a Chocolate Lab Offspring?
Type answer...
37
Fill in the Blanks
How many of the 16 boxes represent a YELLOW Lab Offspring?
Type answer...
38
Fill in the Blanks
Of the FOUR yellow labs, how many will have black noses?
Type answer...
39
Here is my completed Punnett square
40
Poll
How well do you feel you now understand how to do the Epistasis recessive traits?
I understand.
I really don understand, but I am going to ask Mr. Ackert for help.
41
Please do a screen capture of your results following your completion of this video lesson.
Thanks! Mr. A
Epistasis Lesson
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