Hardy-Weinberg Equilibrium + Frequencies

Question 1

Is the frequency of the homozygous dominant genotype (p^2) expected to be larger than the frequency of the dominant allele (p)? Why?

Answer 1

P is larger than P^2 since squaring a decimal number inevitably yields a smaller result

Question 2

What are three conditions that must be respected in order for the sum of p and q to equal 1?

Answer 2

Any 3 of the 5: Random mating, no mutations, no gene flow, large population, no selection

Question 3

Is this population in equilibrium?

AA: 50
Aa: 100
aa: 50

Answer 3

Yes, p+q=1

*Il faut calculer la frequence de AA et de aa et faire la racine, on peut pas calculer la frequence de A et de a directement

Question 4

calculate p^2 + q^2 for the following population:

AA: 172
Aa: 31
aa: 97

Answer 4

p^2 + q^2 = 0.53125

Question 5

In what case can you use expected frequencies to calculate other expected frequencies?

Answer 5

When it is stated that the population is in Hardy-Weinberg equilibrium

Question 6

Does the following population of calico cats evolve?

Generation 1: Real frequency of AA=23/47

Generation 2: Real frequency of AA=69/141

Generation 3: p=0.6995

Answer 6

Convert p into a real frequency and you see that the frequency of AA remains constant. There is thus no evolution

Question 7

How do you find 2pq for a population that is not in equilibrium if you are only given the real allele frequencies, not the genotype frequencies?

Answer 7

It is impossible to find p and q without the genotype frequencies if there is no equilibrium

Question 8

A population of tropical birds living in southern Brazil undergoes an ecosystem change, causing the birds to lose their sense of orientation. Following this change, natural selection occurs in the next generations. Would you expect p+q to equal 1 in the fifth generation? Explain.

Answer 8

No. There is selection, there cannot be equilibrium.

Question 9

Given that there are 336 individuals in a population and that p=0.614797682, solve for x and y.

AA = x 
Aa = 23
aa = y

x and y are a number of individuals, not a frequency

Answer 9

x=127

y=186

Question 10

Real frequency of AA: x
Real frequency of aa: 21x

What is the value of x for which this population is in equilibrium?

Answer 10

x=0.0321