Explain how each evolutionary force can influence a population's allele frequencies Flashcards
What is the definition of allele frequency?
The proportion of a specific allele among all allele copies in a population.
True or False: Natural selection can lead to changes in allele frequencies.
True
What is genetic drift?
A random change in allele frequencies in a population, often having a more significant effect in small populations.
Fill in the blank: __________ is the process by which individuals better adapted to their environment tend to survive and produce more offspring.
Natural selection
What role does mutation play in evolution?
Mutations introduce new alleles into a population, affecting allele frequencies over time.
Multiple choice: Which evolutionary force is characterized by random changes in allele frequencies? A) Natural selection B) Genetic drift C) Gene flow D) Mutation
B) Genetic drift
What is gene flow?
The transfer of alleles or genes from one population to another, which can alter allele frequencies.
True or False: Gene flow can increase genetic diversity within a population.
True
What is the Hardy-Weinberg principle?
A principle that states allele frequencies in a large, randomly mating population will remain constant in the absence of evolutionary forces.
Fill in the blank: The Hardy-Weinberg equilibrium assumes no __________, mutation, migration, or selection.
genetic drift
Multiple choice: Which of the following is NOT an evolutionary force? A) Natural selection B) Genetic drift C) Mutation D) Adaptation
D) Adaptation
What can cause a population to deviate from Hardy-Weinberg equilibrium?
Any evolutionary force such as natural selection, genetic drift, mutation, or gene flow.
True or False: In small populations, genetic drift has a larger impact than in large populations.
True
How does natural selection affect allele frequencies?
Natural selection increases the frequency of beneficial alleles and decreases the frequency of harmful alleles.
What is the founder effect?
A type of genetic drift that occurs when a small group of individuals establishes a new population.
Fill in the blank: The __________ effect occurs when a population’s size is drastically reduced, leading to a loss of genetic variation.
bottleneck
Multiple choice: Which evolutionary force can introduce new genetic variations? A) Genetic drift B) Gene flow C) Natural selection D) All of the above
B) Gene flow
What is stabilizing selection?
A type of natural selection that favors intermediate variants and acts against extreme phenotypes.
True or False: Disruptive selection can lead to speciation.
True
What is directional selection?
A type of natural selection that favors one extreme phenotype over the others, causing a shift in allele frequencies.
Fill in the blank: The __________ model explains how allele frequencies change due to the movement of individuals between populations.
gene flow
How does sexual selection influence allele frequencies?
Sexual selection can lead to increased frequencies of alleles that enhance mating success.
Multiple choice: Which of the following can result in reduced genetic diversity? A) Gene flow B) Genetic drift C) Mutation D) Natural selection
B) Genetic drift
What is the main difference between natural selection and genetic drift?
Natural selection is a non-random process based on fitness, while genetic drift is a random process.
True or False: Mutation rates are generally low, but they are a crucial source of genetic variation.
True
How can environmental changes influence allele frequencies?
Environmental changes can shift selective pressures, favoring different alleles and altering their frequencies.
