GENETICS BASICS
What is the term for differences in characteristics among individuals of the same species?
Variation
What is the total collection of all genes and alleles present in a population?
Answer: Gene pool
What is a change in the DNA sequence called?
Answer: Mutation
A gene is copied into mRNA, and the mRNA is then used to make a protein that affects a trait. What do we call the series of steps that explains how the gene produces the trait?
Answer: Mechanism
What is the process in which organisms with traits better suited to their environment tend to survive and reproduce more?
Answer: Natural selection
What type of variation is caused by differences in DNA sequences?
Genetic variation
What are the different forms of a gene called?
Answer: Alleles
Why are mutations important to evolution?
Answer: They can introduce new genetic variation into a population.
Which mechanism causes allele frequencies to change because of random chance?
Answer: Genetic drift
What is a heritable characteristic that helps an organism survive and reproduce in its environment?
Answer: Adaptation
What molecule contains the genetic instructions that determine inherited characteristics?
DNA
What are the two types of gene pools based on their size?
Answer: Small gene pool and large gene pool
A DNA sequence originally has 5 nucleotides. One nucleotide is added to the sequence, changing its genetic information. What type of mutation occurred?
Answer: Insertion
What are the major mechanisms that cause changes in allele frequencies in populations?
Answer: Natural selection, genetic drift, gene flow, mutation, and recombination
What type of natural selection favors individuals with an average or intermediate trait?
Answer: Stabilizing selection
What is a segment of DNA that contains information for a particular trait or function?
Gene
Which population generally has greater genetic variation: a population with a large gene pool or a small gene pool?
Answer: A large gene pool
A DNA sequence originally has ABCDE. One nucleotide is removed, resulting in ABDE. What type of mutation occurred?
Answer: Deletion
A random flood kills many individuals in a population. The surviving population has much less genetic diversity than before. What type of genetic drift occurred?
Answer: Bottleneck effect
What type of natural selection favors one extreme phenotype?
Answer: Directional selection
A child inherits eye-color-related genetic information from both parents. What process explains the passing of these traits from parents to offspring?
Answer: Heredity
Question: What is the formula for calculating allele frequency? Answer:
Answer:
Allele frequency = Number of copies of an allele รท Total number of alleles in the population
During meiosis, chromosomes exchange sections of DNA, producing new combinations of alleles. What mechanism is this?
Answer: Genetic recombination /Shuffling/ crossing over
A few individuals leave a population and establish a new population on an island. The new population has different allele frequencies from the original population. What is this called?
Answer: Founder effect
In a population of birds, birds with very small and very large beaks survive better because they can access different food sources, while birds with medium-sized beaks struggle. What type of selection is occurring?
Answer: Disruptive selection