Basics U5 Bio Flashcards
(35 cards)
Q: What is variation?
A: Variation is the difference in individuals within a population, caused by mutations and genetic mixing from parents. It can be beneficial or harmful.
Q: What causes variation?
A: Variation is caused by genetic mutations and the merging of genetic material from parents (each contributing 50% of genes).
Q: What is a mutation?
A: A mutation is a spontaneous change in the genetic material of an organism. Mutations can be passed to offspring and may provide a survival advantage.
Q: How do mutations contribute to variation?
A: Mutations introduce new traits that can give organisms a selective advantage, especially when environments change.
Q: What is natural selection?
A: Natural selection is when individuals with favorable variations are more likely to survive and pass on their traits, causing population changes over time.
Q: Key requirement for natural selection?
A: There must be variety within the population for natural selection to occur.
Q: What is speciation?
A: Speciation is the formation of new species when populations become isolated and can no longer interbreed.
Q: How does speciation occur?
A: Speciation happens through two processes: transformation (one species changes into another) and divergence (a new species arises while the original remains).
Q: Types of reproductive barriers that cause speciation?
A: Geographical, habitat, behavioral, temporal, mechanical, and gametic isolation.
Q: What is geographical isolation?
A: Populations are separated by physical barriers (e.g., mountains, rivers) preventing interbreeding.
Q: What is habitat isolation?
A: Populations live in the same area but different habitats, reducing interactions and mating.
Q: What is behavioral isolation?
A: Differences in mating rituals prevent species from recognizing or accepting each other as mates.
Q: What is temporal isolation?
A: Populations mate at different times of the year or day, preventing interbreeding.
Q: What is mechanical isolation?
A: Reproductive organs are physically incompatible between species.
Q: What is gametic isolation?
A: Sperm and egg cannot combine or DNA is too different to support development.
Q: What is adaptive radiation?
A: The rapid diversification of one ancestral species into many different species (e.g. Darwin’s finches).
Q: What is gradualism?
A: Gradual small evolutionary changes accumulate over long periods of time.
Q: What is punctuated equilibrium?
A: Rapid evolutionary changes occur when species first form, followed by long periods of little or no change.
Q: What are the three types of adaptations?
A: Physiological (body processes), structural (physical features), and behavioral (actions and habits).
Q: Example of physiological adaptation?
A: Hibernation or good eyesight.
Q: Example of structural adaptation?
A: Camouflage, sharp claws, or sharp teeth.
Q: Example of behavioral adaptation?
A: Migration, specific mating behaviors.
Q: What is evolution?
A: Evolution is the process by which populations change over time, potentially leading to new species.
Q: Lamarck’s theory of evolution?
A: Believed organisms acquire traits during their lifetime and pass them to offspring; thought evolution was driven by the desire to change.
