7.2.1 The Hardy-Weinberg Principle

• The Hardy-Weinberg equation \( p^2 + 2pq + q^2 = 1 \) describes genotype frequencies
• In the equation \( p + q = 1 \), 'p' represents the frequency of allele A
• For Hardy-Weinberg equilibrium, there should be no natural selection
• The collective set of genes in a population is called the gene
• In the equation \( p + q = 1 \), 'q' represents the frequency of allele a
• What does \( p^2 \) in the Hardy-Weinberg equation represent?

  Frequency of AA
• Natural selection can disrupt Hardy-Weinberg equilibrium by altering allele frequencies.

  True
• The Hardy-Weinberg Principle describes a population where allele and genotype frequencies remain constant from one generation to the next.

  True
• Match the term with its description:

  \( p^2 \) ↔️ Frequency of AA

  \( 2pq \) ↔️ Frequency of Aa

  \( q^2 \) ↔️ Frequency of aa
• A large population size is needed to avoid random fluctuations in allele frequencies due to genetic drift
• The frequency \( q^2 \) represents the proportion of individuals with two recessive alleles (a).
• What is the impact of gene flow on allele frequencies in a population?

  Introduces or removes alleles
• What is the effect of genetic drift on allele frequencies in a small population?

  Random fluctuations
• What is the impact of mutations on allele frequencies in a population according to the Hardy-Weinberg equilibrium?

  Gradual shifts
• What type of mating is required for Hardy-Weinberg equilibrium?

  Random mating
• What are the two factors that help analyze evolutionary changes in populations based on the Hardy-Weinberg equilibrium?

  Gene pool and allele frequencies
• What does the equation \( p + q = 1 \) represent in the Hardy-Weinberg Principle?

  Allele frequencies sum to 1
• The frequency \( 2pq \) in the Hardy-Weinberg equation describes individuals with one dominant and one recessive allele.

  True
• In the Hardy-Weinberg equation \( p + q = 1 \), the variable \( q \) represents the frequency of the recessive allele
• Match the equation with its description:

  p + q = 1 ↔️ Allele frequencies sum to 1

  p^2 + 2pq + q^2 = 1 ↔️ Genotype frequencies sum to 1
• The Hardy-Weinberg equilibrium assumes that allele and genotype frequencies remain constant over generations if conditions are met.

  True
• What is genetic drift in a small population?

  Random fluctuations in allele frequencies
• What does the Hardy-Weinberg Principle describe?

  Genetic equilibrium in populations
• What is the Hardy-Weinberg Principle based on?

  Genetic equilibrium
• What is the significance of a large population size in the Hardy-Weinberg Principle?

  Avoids genetic drift
• If the frequency of allele A (p) is 0.7 and allele a (q) is 0.3, what is the frequency of AA genotypes?

  0.49
• The Hardy-Weinberg equation assumes that genotype frequencies remain constant over generations.


  True
• Match the condition with its significance:

  No Mutations ↔️ Ensures stable allele frequencies

  No Selection ↔️ Prevents changes in genotype frequencies

  Large Population Size ↔️ Avoids genetic drift

  Random Mating ↔️ Prevents biased allele combinations

  No Gene Flow ↔️ Prevents introduction of new alleles
• A stable gene pool maintains constant allele frequencies, providing a baseline for evolutionary studies
• In the equation \( p + q = 1 \), p represents the frequency of allele A
• Mutations are allowed under the Hardy-Weinberg equilibrium conditions.

  False
• The frequency \( p^2 \) represents the proportion of individuals with two dominant alleles (A).


  True
• Random mating ensures individuals mate without preference for specific genotypes
• Mutations cause gradual shifts in allele frequencies, disrupting Hardy-Weinberg equilibrium.


  True
• The Hardy-Weinberg equilibrium is a state where allele and genotype frequencies in a population remain constant
• Genetic drift, which causes random fluctuations in allele frequencies, is avoided by a large population size
• Strong selection pressure favoring dark-colored beetles will maintain the allele frequencies for dark color in equilibrium.

  False
• Match the condition with its description:

  No mutations ↔️ Alleles do not change

  No selection ↔️ All genotypes have equal survival

  Large population size ↔️ Avoids genetic drift

  Random mating ↔️ Individuals choose mates randomly

  No gene flow ↔️ No migration into or out
• What does the term \( p^2 \) in the Hardy-Weinberg equation represent?

  Frequency of AA
• Why does the frequency of wing color alleles remain constant in a stable butterfly population?

  Hardy-Weinberg conditions are met