B Flashcards
What is Evolution?
The change in allele frequencies in a population over generations.
What is DNAs role in evolution?
DNA is the genetic blueprint of all living organisms, and mutations in DNA lead to evolutionary changes.
What is an Allele?
A Variant of a gene that can influence an organisms traits.
What is a Mutation?
A change in DNA sequence that can create new alleles.
What are the three main types of mutations?
1) Base substitution - One nucleotide is replaced by another.
2) Base deletion - One nucleotide is removed.
3) Base insertion - One nucleotide is added.
How do mutations affect proteins?
Mutations can change the amino acid sequence of a protein, potentially altering its function.
What are silent mutations?
Mutations that do not change the amino acid sequence of a protein, potentially altering its function.
What are the main mechanism of evolution?
1) Genetic Drift - Random changes in allele frequencies due to chance events.
2) Genetic Flow - Movement of alleles between populations.
3) Natural Selection - Certain traits become more common because they improve survival and reproduction.
What is Genetic Drift?
A random change in allele frequencies due to change events, often in small populations.
What is a population bottleneck?
A sharp reduction in population size due to disaster, leading to reduced genetic diversity.
What is the Founder Effect?
When a small group of individuals starts a new population with a different allele frequency than the original population.
What is gene Flow?
The movement of alleles between populations, which can introduce new genetic variation.
How does Natual selection work?
1) Inv=divials vary in traits.
2) Some traits provide a survival/reproductive advantage.
3) These advantageous traits become more common in the poulation.
What did Darwin say about natural selection?
More offspring are produced than can survive, leading to competition for resources.
Why is natural selection not random?
It favours traits that increase survival and reproduction, unlike genetic drift.
What is wrong with the term “survival of the fittest”?
Evolution is not just about survival but about reproductive success.
Do individuals evolve?
No, evolution occurs across generations, not within an individual’s lifetime.
Are humans more highly evolved than other species?
No, all species are adapted to their simple or complex environments.
Does evolution lead to perfect adaption?
No, Evolution depends on environmental changes, and adaptation is an ongoing process.
How did the Peppered Moth population Evolve?
During the industrial revolution, black moths became more common due to pollution making trees darker, favouring their camouflage.
What does the Rock Pocket Mouse example show?
Natural selection acts on coat colour to match the environment, demonstrating how mutations can be beneficial.
