# Evolution: Hardy-Weinberg equilibrium

Evolution
Chapter 12&13

Lesson 4: Hardy-Weinberg equilibrium
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Slide 1: Tekstslide
BiologieMiddelbare schoolvwoLeerjaar 4

In deze les zitten 35 slides, met interactieve quizzen, tekstslides en 4 videos. Lesduur is: 45 min

## Onderdelen in deze les

Evolution
Chapter 12&13

Lesson 4: Hardy-Weinberg equilibrium

#### Slide 1 -Tekstslide

Learning objectives
• You can distinguish between allele frequency, genotype frequency, gene, allele and gene pool
• You can explain the requirements necessary for a population to meet the Hardy-Weinberg equilibrium
• You can use the Hardy-Weinberg equations to perform calculations on population genetics

#### Slide 2 -Tekstslide

Gene
Allele
Phenotype
Genotype
Gene pool
Version of a gene
All copies of a gene in a population
Section of DNA that controls a particular trait
Set of alleles
Observable features

#### Slide 3 -Sleepvraag

1
2
3
1: two W alleles
2: one W allele and one w allele
3: two w alleles

#### Slide 4 -Tekstslide

Total number of alleles?
Number of W?
Number of w?

#### Slide 5 -Open vraag

Total: 18
W: 13
w: 5
Allele frequency
timer
3:00
Calculate allele frequency of W and the allele frequency of w

#### Slide 6 -Tekstslide

Total: 18
W: 13
w: 5
Allele frequency
Allele frequency of W:13/18=0,72
Allele frequency of w: 5/18=0,28
Total=1,00
Make sense?

#### Slide 7 -Tekstslide

Allele frequency formula
We assign p to the dominant allele
We assign q to the recessive allele

Result:
p + q = 1

#### Slide 8 -Tekstslide

What is represented by the letter q?
A
the gene pool
B
the dominant allele
C
the recessive allele
D
the genotype

If p= 0,7, q is?
A
0,3
B
1,0
C
0,2
D
0,7

#### Slide 10 -Quizvraag

If the frequency of the dominant allele is 0,6, the frequency of p is?
A
1,0
B
0,4
C
0,5
D
0,6

#### Slide 11 -Quizvraag

Genotype frequency
• Frequency WW?
• Frequency Ww?
• Frequency ww?
timer
2:00

#### Slide 12 -Tekstslide

Genotype frequency
Usually more interesting
• Frequency WW?:
6/9=0,67
• Frequency Ww?
1/9=0,11
• Frequency ww?
2/9=0,22

#### Slide 13 -Tekstslide

Calculate chance of genotype WW
= W
= w
1. Frequency W in population
2. Frequency = chance to 'pull'
3. Chance to pull WW = chance to pull W x chance to pull W
timer
2:00

#### Slide 14 -Tekstslide

Calculate chance of genotype WW
= W
= w
1. Frequency W in population
2. Frequency = chance to 'pull'
3. Chance to pull WW = chance to pull W x chance to pull W
Frequency W = 0,7
Chance WW = 0,7 x 0,7 =0,49

#### Slide 15 -Tekstslide

A population of 150 individuals has an allele frequency of 0,6 for the dominant allele (B) and a frequency of 0,4 for the recessive allele (b). Use the Hardy-Weinberg equation to determine the frequency of the genotype (bb).
A
0,36
B
0,4
C
0,16
D
0,24

#### Slide 16 -Quizvraag

Turning it into p and q
If WW is W x W, how do you write it using p?
If ww is w x w, how do you write it using q?

#### Slide 17 -Tekstslide

Turning it into p and q
If WW is W x W, how do you write it using p?
If ww is w x w, how do you write it using q?
p x p = p2
q x q = q2

#### Slide 18 -Tekstslide

How would you calculate the chance of a heterozygote?

#### Slide 19 -Woordweb

Turning it into p and q
How would you calculate the chance of a heterozygote?

#### Slide 20 -Tekstslide

Calculating genotype frequencies
Homozygous dominant: p x p = p2
Heterozygous: p x q + q x p = 2pq
Homozygous recessive: q x q = q2

In total:
p2 + 2pq + q2 = 1
Total is 1 because together they make up all genotypes

#### Slide 21 -Tekstslide

q2 is the frequency of:
A
the recessive allele
B
the dominant allele
C
the recessive genotype
D
the dominant genotype

#### Slide 22 -Quizvraag

p=0,2. What is the frequency of the recessive phenotype?
A
0,04
B
0,4
C
0,32
D
0,64

#### Slide 23 -Quizvraag

Give the frequencies

#### Slide 25 -Tekstslide

Hardy-Weinberg equilibrium
p+q=1 and p2+2pq+q2=1 are formulas that belong to the Hardy-Weinberg equilibrium.

They are used to track allele frequencies and see if they chance/ make predictions about and how they will change.

#### Slide 26 -Tekstslide

If a population is in a Hardy-Weinberg equilibrium this means the allele frequencies are not changing. Therefore, there is no evolution!
Equilibrium only exists if these five requirements are met
Remember the five fingers of evolution?

#### Slide 27 -Tekstslide

What if requirements are not met?
Evolution!

#### Slide 28 -Tekstslide

A population's recessive allele frequency is 25%. What is the percentage of the Homozygous Dominant genotype?

#### Slide 29 -Open vraag

64% of the population has the recessive phenotype. What is the percentage of the heterozygous genotype?

#### Slide 30 -Open vraag

Homework
Worksheet Hardy-Weinberg on Classroom