Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
23 Cards in this Set
- Front
- Back
|
What is natural selection?
|
Natural selection is the impact of all abiotic and biotic factors in a specific environment on the allele frequency of a population.
|
|
|
What does natural selection result in?
|
Natural selection results in populations that are better adapted to reproduce in a specific environment.
|
|
|
What is essential for natural selection to occur?
|
genetic variation
differential reproduction heredity |
|
|
What is the source of new alleles in a population?
|
Mutation
|
|
|
What factors can act as agents of natural selection?
|
All abiotic (non-living) and and biotic (living) factors can act as agents of natural selection.
|
|
|
What are some examples of abiotic factors?
|
Abiotic factors are non-living.
temperature cloud cover water rain snow fog water currents waves |
|
|
What are some examples of biotic factors?
|
Biotic factors are living.
competition predation (carnivory, herbivory) symbiosis (disease, mutualism, parasitism) |
|
|
What does natural selection increase?
|
Natural selection increases the ability to reproduce in a specific environment.
|
|
|
What are the results of natural selcton?
|
Natural selection results in populations that are better adapted to reproduce in a specific environment.
|
|
|
Alleles that increase reproduction always _________ in frequency in the future.
|
increase
|
|
|
Alleles that reduce reproduction always ________ in frequency in the future.
|
decline
|
|
|
What does natural selection impact?
|
Natural selection impacts the frequency of alleles that affect reproduction in a specific environment.
|
|
|
What does sexual reproduction increase in populations?
|
genetic variation
|
|
|
What is the source of new alleles in a population?
|
mutation
|
|
|
Besides mutation, what else can create new alleles into populations?
|
migration
|
|
|
Explain meiosis.
|
Meiosis generates all possible combinations of our maternal and paternal chromosomes in the gametes we produce.
|
|
|
Explain crossing-over in meiosis.
|
Crossing-over during meiosis forms new combinations of maternal and paternal alleles on a single chromosome that can cause new phenotypes.
|
|
|
Why do some populations that reproduce asexually consist of genetically-diverse individuals?
|
Due to mutation, genetic variation does occur in populations that reproduce asexually.
|
|
|
What is the benefit of natural selection?
|
Natural selection maximizes the reproductive ability of individuals in an environment (increases "fitness").
|
|
|
What is necessary to coordinate reproduction?
|
A successful genome has the alleles necessary to coordinate reproduction so it is transmitted to the next generation.
|
|
|
What is the benefit of negative health consequences?
|
Alleles with negative health consequences exist in populations because they increase reproduction.
|
|
|
What is the benefit of disease-promoting alleles?
|
Disease-promoting alleles exist in populations because they increase reproduction in heterozygotes.
|
|
|
What is the heterozygote advantage?
|
One copy of the sickle-cell allele increases resistance to malaria.
|
