# Hardy Weinberg

Evolution

Hardy-Weinberg equilibrium
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Slide 1: Tekstslide
BiologieMiddelbare schoolvwoLeerjaar 4

In deze les zitten 30 slides, met interactieve quizzen en tekstslides.

## Onderdelen in deze les

Evolution

Hardy-Weinberg equilibrium

#### Slide 1 -Tekstslide

Remember the five fingers of evolution: What are the five processes that lead to evolution?

#### Slide 2 -Tekstslide

Five processes that lead to evolution
1. Small population/genetic drift: chance will start to play a role
2. Non-random mating/sexual selection
3. Mutation
4. Gene flow: immigration and emigration
5. Natural selection
1
4

#### Slide 3 -Tekstslide

Question
A short-haired heterozygous cat mates with another short-haired heterozygous cat. The gene for short-haired is dominant. What are the chances on a heterozygote? What are the chances on a short-haired cat?
What is the total chance on a short-haired or long-haired cat?

#### Slide 6 -Tekstslide

What is a population?

#### Slide 7 -Open vraag

What is a gene pool?

#### Slide 13 -Tekstslide

Hardy-Weinberg: waar komt het vandaan?

#### Slide 14 -Tekstslide

Look at the following formula:

this calculates?
p2+2pq+q2=1

#### Slide 15 -Tekstslide

Question
In sheep, a white coat is produced under the influence of the dominant allele H and a black coat due to the recessive allele h. In a flock of sheep, 891 have white and 9 have black fur.

The Hardy-Weinberg rule applies to this population.

Calculate the frequency of the allele H.

#### Slide 16 -Tekstslide

Total number of sheep: 891 + 9 = 900
Frequency animals with black fur: 9/900=0.01 = q2
-> q = 0.1
-> p = 0.9 (frequency of allele H)

#### Slide 17 -Tekstslide

Question
In a population of 100 birds, the allele frequency for the recessive white-wing allele is 0.4.

How many birds in that population have white wings?

#### Slide 18 -Tekstslide

q = 0.4

-> q2 = 0.16
-> number of birds with white wings: 0.16 x 100 = 16

#### Slide 25 -Tekstslide

Did you achieve these learning objectives?

- You can explain what the Hardy Weinberg principle is used for in evolution.
- You can explain what the five conditions are for the Hardy Weinberg equilibrium to remain constant.
- You can use the Hardy-Weinberg equation to calculate genotype and allele frequencies from observed phenotype frequencies.

#### Slide 26 -Tekstslide

Work to be done
Biozones 209 - 212
2 fill-in worksheets to help you to make a summary of 15.3

#### Slide 27 -Tekstslide

Albinism occurs with a frequency of 1/20,000 people. How many people are carriers?

#### Slide 28 -Open vraag

Albinism in 1 on 20.000 people
According to Hardy Weinberg's equilibrium:
p2 + 2pq + q2 = 1 and p + q = 1

Albinism is the phenotype of aa -> frequency q2
-> q2 = 1/20,000 = 0.00005
-> q = 0.007 (p+q=1) p = 1 - 0.007 = 0.993
-> frequency carriers: 2pq = 2 x 0.007 x 0.993 = 0.00139
-> in a population of 20,000 people: 0.00139 x 20,000 = 278 carriers