Create a Venn diagram comparing phenotype and genotype Use the words physical appearance genetic makeup heterozygous homozygous describes an organism purple tall Pp greenpp Describe the difference between complete dominance incomplete dominance and codominance ID: 736628
Download Presentation The PPT/PDF document "Punnett Squares Tuesday - Bellwork" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Punnett SquaresSlide2
Tuesday - Bellwork
Create a Venn diagram comparing phenotype and genotype: Use the
words physical appearance, genetic makeup, heterozygous, homozygous, describes an organism, purple, tall, Pp, green,pp
Describe the difference between complete dominance, incomplete dominance, and codominance
IFC: What is the first step in the scientific method? A. make a hypothesis B. Ask a question C. draw conclusions D. do background researchSlide3
Wednesday bellwork – 10/23
In a cross between a yellow fish and a blue fish all of the offspring are green. What kind of dominance is this?
In some flowers blue and white are codominant. Describe the phenotypes of each of these flowers
BB WW BW
IFC:
Chemists often make models of molecules using balls to show atoms and sticks to show bonds.
The models help them see what the molecules might look like.
What is a limitation of this model?
The models wont last as long as real molecules
The colors of the balls and sticks would not show the molecule’s real color
Real molecules are very small and complex, models could only approximate what they look like.
Chemists are bad model makers so they would not be very usefulSlide4
Science Fair Topic and Question research
Today you will find a testable question for your science project.
Log in to my website:
akbrownscience.weebly.com
Choose the science fair tab. You will find links to sites with topic and question ideas.
Look through the topic ideas and questions to help you get an idea for your project – choose at least 3 today and write them in your science fair log
Remember to write down the site you got the ideas from so you can find them again
When you finish, begin looking for background research on your project.Slide5
Thurs. Bellwork – 10/24
In Pea plants, round peas (R) are dominant over wrinkled peas (r).
What is the genotype of a homozygous recessive pea plant?
What is its phenotype?
What is the genotype of a heterozygous pea plant
What is its phenotype?
IFCSlide6
EQ: how are patterns of inheritance studied?
OBJ: I can predict patterns in heredity because I can create Punnett squares and read pedigrees
SC.7.L.16.2
Determine the probabilities for genotype and phenotype combinations using Punnett Squares and pedigrees.Slide7
What is probability?
Probability
is the likelihood that a particular event will occur
It can be written as a:
Fraction ____
Percent ____
Ratio ____
1/4
25%
1:3Slide8
What is a Punnet Square?
A
Punnett
square is a model that helps you find the probability of different outcomes from genetic crossesSlide9
COIN FLIP
There are 2 possible outcomes:
HEADS TAILS
capital
http://www.arborsci.com/CoolStuff/CoinFlip.jpg
The chance the coin will land on either one is:
______ ______ _____
Alleles separate randomly just like a coin flip. . . So can use probability to predict outcomes of genetic crosses.
1/2
50%1:1Slide10
Probability and Tossing Coins
If you toss a coin, what is the probability of getting heads?
Tails?
If you toss a coin 6 times, how many heads and how many tails would you expect to get?
Working with a partner, have one person toss a coin 6 times while the other person tallies the results on a sheet of paper. Then, switch tasks to produce a separate tally of the second set of 6 tosses. Slide11
Assuming that you expect 3 heads and 3 tails in 6 tosses, how do the results of your tosses compare? How about the results of your partner’s tosses? How close was each set of results to what was expected?
Add your results to those of your partner to produce a total of 12 tosses. Assuming that you expect 6 heads and 6 tails in 12 tosses, how close are these results to what was expected?
If you compiled the results for the whole class, what results would you expect?
How do the expected results differ from the observed results?Slide12
A Punnett square helps us predict the
probability
that an offspring with a particular
genotype
and phenotype will be produced
What is a Punnett Square
I
wish I could make a punnett squareSlide13
To Make a Punnett square there are a few simple steps to follow:
1)
draw a
box
and divide it into
four
parts
How do I create a Punnett Square?Slide14
2)
label the
left
hand side of the box with the genotype of one
parent
(R=Red, r=White)
R
r
How do I create a
Punett
Square?Slide15
3) label the
top
of the box with the genotype of the other
parent
R
r
r
r
How do I create a Punnett SquareSlide16
4) In the middle boxes place
2
letters. One letter comes from the
left
side and one from the
top
R
r
r
r
RrrrRrrrHow do I create a Punnett SquareSlide17
You now know the possible genotypes for the offspring of these two parents
.
The genotypes and phenotypes can be given a ratios, fractions, or %s
How do I Interpreti a Punnett SquareSlide18
Complete and check with your shoulder partner
. A cross between a female with straight hair (HH) and a male with curly hair (hh)
genotypes___________
phenotypes__________()
Practice ProblemsSlide19
What are the possible genotypes of the offspring?
What are the possible phenotypes of their offspring?
(% and color)
Black eyes (B) are dominant over red eyes (b) in some rats.
Make a cross between two HETEROZYGOUS rats.
75 % black eyes
25% red eyes
B b
B
b
BB Bb Bb bb25% BB
50% Bb25% bbSlide20
What are the possible genotypes of the offspring?
What are the possible phenotypes of their offspring?
(% and color)
Make a cross between a Homozygous Dominant rat and a homozygous recessive rat.
100% Black eyes
B B
b
b
Bb Bb
Bb Bb
100% eterozygousSlide21
2. A cross between a black dog (Bb) and a brown dog (bb)
genotypes_____________ (#BB:#Bb:#bb)
phenotypes____________ (#Black:#Brown)
Practice ProblemsSlide22
3. A cross between a yellow corn (Yy) and another yellow corn (Yy) (y = white corn)
genotypes_________________
phenotypes_______________
Practice ProblemsSlide23
Guinea Pig Punnet squares
Write the possible outcomes for the guinea pig offspring in the boxes
Cut out the appropriate guinea pig and glue in the spaceSlide24
Bellwork:
While scientists already know a great deal about DNA, they continue to learn more about its role in
genetics.What
is the basis of scientists’ current understanding of DNA?
A. They guess how they think it works.
B. They use combined empirical evidence from many scientists.
C. They only use evidence that they have personally proven.
D. They assume they already know all there is to know, even when evidence contradicts that assumption
.
IFC
3. Create a Punnett square to show a cross between a yellow corn (Yy) and another yellow corn (Yy) (y = white corn)genotypes_________________ phenotypes_______________Slide25
Celebrity punnett squares
You will pick 2 random celebrities
Their traits are listed on their picture – do not destroy them I need them all day
Make 6
punnett
squares to determine the genotypes and phenotypes of their offspring