All flashcards
Flashcard 1: Which process creates new alleles in a population?
Answer: Mutation. Only mutations can create brand new genetic variants.
Flashcard 2: Which option best indicates genetic variation: different fur colors or different ages?
Answer: Different fur colors. Fur color is genetic; age is environmental.
Flashcard 3: Which data type most directly measures genetic variation: allele frequencies or population size?
Answer: Allele frequencies. Shows the proportion of each allele variant in the population.
Flashcard 4: Identify the population with greater genetic variation: all AA vs AA, Aa, and aa present.
Answer: AA, Aa, and aa present. Three genotypes means more genetic diversity than just one.
Flashcard 5: What is genetic drift?
Answer: Random changes in allele frequencies, strongest in small populations. Like flipping coins - chance affects which alleles survive.
Flashcard 6: What is independent assortment?
Answer: Random separation of chromosome pairs into gametes. Each gamete gets a random mix of maternal and paternal chromosomes.
Flashcard 7: What is crossing over?
Answer: Exchange of DNA between homologous chromosomes during meiosis. Creates new allele combinations on chromosomes.
Flashcard 8: Which process increases variation by shuffling alleles during meiosis?
Answer: Genetic recombination. Creates new combinations of existing alleles.
Flashcard 9: Which type of selection favors one extreme phenotype and reduces variation?
Answer: Directional selection. Pushes population toward one trait value.
Flashcard 10: Which process moves alleles between populations when individuals migrate and reproduce?
Answer: Gene flow. Migration spreads genetic diversity between groups.
Flashcard 11: Which process shuffles alleles during meiosis to increase variation?
Answer: Crossing over (recombination). Chromosomes exchange segments, creating new combinations.
Flashcard 12: What is a genotype?
Answer: An organism’s allele combination for a gene. Written as letters (e.g., AA, Aa, aa).
Flashcard 13: What is a phenotype?
Answer: Observable trait produced by genes and environment. What you see results from genes plus environmental factors.
Flashcard 14: Which term means two identical alleles for a gene?
Answer: Homozygous. Same alleles inherited from both parents (AA or aa).
Flashcard 15: Which term means two different alleles for a gene?
Answer: Heterozygous. Different alleles from each parent (Aa).
Flashcard 16: What is a mutation in DNA?
Answer: A change in the DNA sequence. Can be harmful, beneficial, or neutral.
Flashcard 17: Which process creates new alleles and is the ultimate source of variation?
Answer: Mutation. Only mutations can create brand new genetic variants.
Flashcard 18: Which process randomly separates chromosomes into gametes, increasing variation?
Answer: Independent assortment. Chromosomes sort randomly into sex cells.
Flashcard 19: Which event combines alleles from two parents and increases variation?
Answer: Random fertilization. Any sperm can fertilize any egg, mixing parental genes.
Flashcard 20: What is gene flow?
Answer: Movement of alleles into or out of a population via migration. Introduces new alleles when organisms move between groups.
Flashcard 21: Which type of variation is caused by different alleles (not environment)?
Answer: Genetic variation. Inherited differences, not changes from lifestyle or environment.
Flashcard 22: Identify the best evidence of genetic variation: different eye colors or different suntans?
Answer: Different eye colors. Eye color is inherited; suntans are environmental.
Flashcard 23: What is a gene locus?
Answer: The specific location of a gene on a chromosome. Like an address for finding a gene on its chromosome.
Flashcard 24: What is genetic variation within a population?
Answer: Differences in DNA (alleles) among individuals of the same species. These differences create the variety we see within a species.
Flashcard 25: Which situation is an example of gene flow: mutation in one bird or birds migrating and breeding?
Answer: Birds migrating and breeding. Movement and reproduction transfers alleles between populations.
Flashcard 26: Identify the genotype(s) that are homozygous for a gene with alleles A and a.
Answer: AA and aa. Both have matching alleles (AA has two A's, aa has two a's).
Flashcard 27: Identify the genotype that is heterozygous for a gene with alleles A and a.
Answer: Aa. Has two different alleles (one A, one a).
Flashcard 28: Which type of selection favors the average phenotype and reduces variation?
Answer: Stabilizing selection. Eliminates extremes, keeping the middle range.
Flashcard 29: Which type of selection favors both extremes and can increase variation?
Answer: Disruptive selection. Eliminates the middle, creating two distinct groups.
Flashcard 30: What is a mutation in genetics?
Answer: A change in the DNA sequence. Can be caused by errors in DNA copying or environmental factors.