Download probability and punnett squares

Name:
Chapter 11 – Introduction to Genetics
Section 11-2 – Probability and Punnett Squares
1.
Define probability.
1.
the likelihood a particular event will happen
2.
How is probability expressed?
2.
as a percent or fraction
3.
Probability Example:
What is the probability that a coin will
land heads up?
3.
1 out of 2
4.
How can we use probability to predict
traits?
4.
punnett squares use probability to predict
combinations of alleles in a genetic cross
5.
What is a Punnett square?
5.
a diagram used to predict the outcome of a genetic
cross
6.
How do we represent dominant alleles in
a genetic cross?
6.
capital letter
7.
How do we represent recessive alleles
in a genetic cross?
7.
lowercase letter
8.
Define homozygous.
8.
organisms that have two of the same alleles
(letters)
9.
50% or ½
Circle the choices that are examples of
homozygous dominant.
AA
Circle the choices that are examples of
homozygous recessive.
ee
Define heterozygous.
9.
Circle the choices that are examples of
heterozygous.
10.
When will the dominant gene be
expressed?
Ff
KK
ee
qq
Rr
TT
HH
Oo
nn
Uu
ww
organisms that have two different alleles (letters)
MM
10.
Gg
Nn
dd
Ff
Gg
ii
any time the dominant gene (capital letter) is
present
Kk
Circle the choices that are examples
where the dominant gene will show.
11.
When will the recessive gene be
expressed?
AA
11.
Circle the choices that are examples
where the recessive gene will show.
Dd
EE
ff
Jj
RR
Ss
only when there are two recessive alleles
(lowercase letters)
aa
Gg
KK
Oo
PP
12.
Define phenotype. Give an example.
12.
physical characteristics of an organism
ex. brown eyes
13.
Define genotype. Give an example.
13.
genetic makeup of an organism
ex. BB, Bb, bb
ss
tt
Practice making a Punnett square.
In guinea pigs, black coat color, B, is dominant to brown coat color, b. Show the genetic cross between a
black male, Bb, and a brown female, bb.
1. Make a key showing possible
allele combinations.
3. Show the Punnett square.
2. List the parents’ genotypes and
possible gametes.
4. List the genotypes of the
offspring.
5. List the phenotypes of the
offspring.
Practice making a Punnett square.
In guinea pigs, black coat color, B, is dominant to brown coat color, b. Show the genetic cross between a
homozygous brown male and a homozygous black female.
1. Make a key showing possible
allele combinations.
2. List the parents’ genotypes
and possible gametes.
3. Show the Punnett square.
4. List the genotypes of the
offspring.
5. List the phenotypes of the
offspring.