Vocabulary Basics
Q: What term describes differences in traits among individuals of the same species?
A: Variation
Q: Which actually survives or dies due to natural selection—individuals or populations?
A: Individuals
Q: Two different alleles for a trait.
A: Heterozygous
Q: A trait is inherited and present in many individuals, but suddenly disappears after several generations. What is the most likely reason?
A: The environment changed
Q: In undisturbed layers, which is oldest: top or bottom?
A: Bottom
Q: What is the term for a trait that increases survival or reproduction?
A: Adaptation
Q: What term describes the observable form of a trait?
A: Phenotype
Q: If a recessive trait increases survival, what will happen to it over generations?
A: It becomes more common
Q: A population has variation in beak size. Food becomes harder to crack. Which beaks will likely become more common?
A: Larger, stronger beaks
Q: Fossils of giant penguins like Pedro are found on continents that are now far apart. What does this suggest about Earth’s past?
A: Those continents were once connected (Pangea)
Q: What is the term for an organism’s ability to survive and reproduce?
A: Fitness
Q: The physical expression of a recessive allele only occurs when the organism is?
A: Homozygous recessive
Q: Traits that help an organism survive are called?
A: Adaptive traits
Q: What is it called when humans select which traits are passed on?
A: Artificial selection
Q: The study of fossils is called?
A: Paleontology
Q: What do we call a factor in the environment that affects survival?
A: Selective pressure
Q: What is the only way new alleles are introduced into a population?
A: Mutation
Q: Which type of trait can be passed from parent to offspring?
A: Heritable trait
Q: A population with no variation for a trait: can natural selection act on it? (Yes or No)
A: No
Q: Fossils show modern penguins are smaller but faster swimmers than ancient penguins. What change could explain this?
A: Increased predation pressure
Q: What process causes helpful traits to become more common over generations?
A: Natural selection
Q: An organism that shows the dominant phenotype but has a recessive allele is called?
A: Heterozygous
Q: Two parents with genotype Aa and AA have offspring. What fraction is expected to be homozygous recessive?
A: 0%
Q: Percent of heterozygous offspring from two heterozygous parents (Aa × Aa)?
A: 50%
Q: If penguin fossils are found far inland, what does this suggest about that area long ago?
A: It was once near water