cie a level biology chapter 17 evolution
How does lateral gene transfer affect variation? - Answer Occurs between organisms
of the same species or organisms of different species. It increases genetic variation in
any specie that picks up the "new" genes.
Height in humans are an example of what kind of trait? - Answer -Polygenetic
Each gene of a polygenic trait often has two or more ______. - Answer Alleles
If a trait made an organism less likely to survive and reproduce, what would happen to
the allele for that trait? - Answer Fewer copies of the allele will pass for future
generations and the allele could disappear from the gene pool completely
If a trait had no effect on an organism's fitness, what would likely happen to the allele for
that trait? - Answer The allele wouldn't be under pressure from natural selection and
its frequency would almost stay the same
What effect does stabilizing selection have on variation in a population? - Answer It
would decrease the variation a population
Directional Graph - Answer Individuals at one end of the curve have higher fitness
than individuals in the middle or at the end
Stabilizing Graph - Answer Individuals near the center of the curve have higher
fitness than individuals at either end
Disruptive Graph - Answer Individuals at the upper and lower ends of the curve have
higher fitness than individuals near the middle
Genetic Equilibrium - Answer Allele frequencies in its gene pool don't change
Speciation - Answer Formation of new species
What does it mean for two species to be reproductively isolated from each other? -
Answer It means they no longer interbreed and the gene pool splits
, What must happen in order for a new species to evolve? - Answer Populations must
be reproductively isolated from each other
What is an example of temporal isolation? - Answer Two or more species reproduce
at different times
Single-Gene Trait - Answer A trait controlled by a single gene
Polygenic Traits - Answer Controlled by two or more genes
How is genetic variation in organisms studied? - Answer At a level of a population not
the individual.
Population - Answer Group of individuals of the same species that live in the same
area
Gene Pool - Answer All of the genes that are present in a population, members of a
population of species interbreed, therefore they share a common group of genes
Relative (Allelic) Frequency of an allele - Answer Number of times that the allele
occurs in a gene pool compared to the number of time other alleles for the same gene
occur
Gene Shuffling - Answer Happens during meiosis
Crossing Over - Answer Happens during Prophase 1
How do new alleles arise? - Answer Random mutations, gene shuffling, crossing
over, and sexual reproduction
Evolution - Answer Any change in the relative frequency of alleles in a population
If the frequency of the allele changes then - Answer The population is evolving
Inheritable variation can be expressed by - Answer -Single gene trait (freckles) or by
polygenic (like eye color in humans)
How many genes control the trait? - Answer The number of phenotypes produced for
a given trait
How does lateral gene transfer affect variation? - Answer Occurs between organisms
of the same species or organisms of different species. It increases genetic variation in
any specie that picks up the "new" genes.
Height in humans are an example of what kind of trait? - Answer -Polygenetic
Each gene of a polygenic trait often has two or more ______. - Answer Alleles
If a trait made an organism less likely to survive and reproduce, what would happen to
the allele for that trait? - Answer Fewer copies of the allele will pass for future
generations and the allele could disappear from the gene pool completely
If a trait had no effect on an organism's fitness, what would likely happen to the allele for
that trait? - Answer The allele wouldn't be under pressure from natural selection and
its frequency would almost stay the same
What effect does stabilizing selection have on variation in a population? - Answer It
would decrease the variation a population
Directional Graph - Answer Individuals at one end of the curve have higher fitness
than individuals in the middle or at the end
Stabilizing Graph - Answer Individuals near the center of the curve have higher
fitness than individuals at either end
Disruptive Graph - Answer Individuals at the upper and lower ends of the curve have
higher fitness than individuals near the middle
Genetic Equilibrium - Answer Allele frequencies in its gene pool don't change
Speciation - Answer Formation of new species
What does it mean for two species to be reproductively isolated from each other? -
Answer It means they no longer interbreed and the gene pool splits
, What must happen in order for a new species to evolve? - Answer Populations must
be reproductively isolated from each other
What is an example of temporal isolation? - Answer Two or more species reproduce
at different times
Single-Gene Trait - Answer A trait controlled by a single gene
Polygenic Traits - Answer Controlled by two or more genes
How is genetic variation in organisms studied? - Answer At a level of a population not
the individual.
Population - Answer Group of individuals of the same species that live in the same
area
Gene Pool - Answer All of the genes that are present in a population, members of a
population of species interbreed, therefore they share a common group of genes
Relative (Allelic) Frequency of an allele - Answer Number of times that the allele
occurs in a gene pool compared to the number of time other alleles for the same gene
occur
Gene Shuffling - Answer Happens during meiosis
Crossing Over - Answer Happens during Prophase 1
How do new alleles arise? - Answer Random mutations, gene shuffling, crossing
over, and sexual reproduction
Evolution - Answer Any change in the relative frequency of alleles in a population
If the frequency of the allele changes then - Answer The population is evolving
Inheritable variation can be expressed by - Answer -Single gene trait (freckles) or by
polygenic (like eye color in humans)
How many genes control the trait? - Answer The number of phenotypes produced for
a given trait
