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3IBA 2022-23 class made Quizlet
What is needed for natural selection to occur?
Variation among members of the same species
What causes variation between individuals in a species?
Mutation, meiosis and sexual reproduction
What are characteristics that make an indvidual suited to its environment and way of life?
Adaptations
How much offspring to species tend to produce?
More than the environment can support
Who tends to survive and produce more offspring?
Individuals that are better adapted
Who tends to die and/or produce fewer offspring?
Less well adapted individuals
What do individuals that reproduce pass on to their offspring?
Characteristics
What does natural selection increase the frequency of?
Characteristics that make individuals better adapted
What does natural selection decrease the frequency of?
Characteristics that don't make individuals better adapted
What does the increase/decrease of frequencies of certain characteristics lead to?
Changes within the species
What is genetic drift?
Change in allele frequency in a gene pool
How does meiosis cause variation?
Production of gametes with unique combinations of alleles increases genetic variation of individuals within the species
When does selection take place?
When there is something to choose from
What does natural selection favor?
Characteristics that support the survival fo the species
What are some environmental factors that affect survival chances?
Predation, competition for food and disease
What processes cause variation during meiosis?
Crossing over and random assortment
What is variation?
Differences between species
What trait was different between Darwin's finches?
Their beak
What is natural selection?
The process by which organisms that are better adapted to their environment survive, reproduce, and pass on their advantageous alleles, causing advantageous characteristics to increase in frequency within a population
Examples of natural selection and variation
Darwin's finches, peppered moth, antibiotic resistance
What is the speciation?
It is the process of individuals in a population separating from the rest of the population and developing unique characteristics
What is the only way that variation can arise in a species asexually?
Mutation
What can be a problem with succession linked to species already living in that habitat?
The successive species could outcompete the native species, becoming an invasive species
How did the polar bear evolve to get white fur?
Over time, the bears with brown or darker fur had a harder time getting food and died
What are adaptations?
Adaptations are features that make an individual better suited to its environment and way of life.
Why is it important for a population to restrict its use of antibiotics?
Bacteria mutate
What is pentadactyl?
The genetic variation of having 5 fingers on one hand, e.g. like humans, whales, dogs and generally a lot of modern living animals.
Which of the following will promote variation in a species?
Meiosis
Fertilization
Why has antibiotic resistance evolved in bacteria?
Bacteria showing resistance to antibiotics survive after antibiotics are used.
Random orientation
Metaphase I gives rise to huge genetic variation
Low fitness
Unfavorable alleles decrease over time due to death before reproduction
High fitness
Favorable alleles increase in populations as individuals have more offspring
Plasmids
A small ring of DNA
Contains a copy of some genes
Plasmid can be transferred to other bacteria
Antibiotic resistance can spread faster because of this
What is the mechanism of natural selection?
Variations amongst individuals of a population are selected by a changing environment.
Which process has NOT the greatest effect in determining which members of a population are most likely to survive until reproductive age?
Evolution
Meiosis
Hybridization
Note 
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