$CATEGORY: Science - Khan Academy/9.Heredity & Evolution/9.Heredity & Evolution--Speciation

//Multiple Choice

Speciation is the process of\:
{
  ~ Extinction of species
  = Formation of new species
  ~ Mutation in genes
  ~ Migration of species
}

Which of the following is a factor that leads to speciation?
{
  ~ Genetic drift
  ~ Gene flow
  ~ Natural selection
  = All of the above
}

Geographical isolation leads to speciation because\:
{
  ~ It allows interbreeding
  = It prevents gene flow between populations
  ~ It increases genetic similarity
  ~ It leads to mutation
}

Which of these is an example of speciation?
{
  = Finch species on Galápagos Islands
  ~ Breeding of dogs
  ~ Cross-pollination in plants
  ~ Cloning of sheep
}

The primary cause of speciation is\:
{
  = Geographical barriers
  ~ Similar environmental conditions
  ~ Lack of genetic variation
  ~ Overproduction of offspring
}

Which mechanism does not lead to speciation?
{
  ~ Genetic drift
  ~ Mutation
  = Asexual reproduction
  ~ Reproductive isolation
}

Reproductive isolation can occur due to\:
{
  ~ Physical barriers
  ~ Behavioral differences
  ~ Temporal differences
  = All of the above
}

The process of speciation is slow because it depends on\:
{
  ~ Sudden environmental changes
  = Gradual accumulation of genetic differences
  ~ Rapid reproduction
  ~ Immediate isolation
}

Which of these is not an example of speciation?
{
  ~ Formation of Darwin’s finches
  ~ Emergence of antibiotic-resistant bacteria
  = Development of hybrid crops
  ~ Evolution of polar bears from brown bears
}

Speciation due to geographical isolation is called\:
{
  ~ Sympatric speciation
  = Allopatric speciation
  ~ Adaptive radiation
  ~ Artificial selection
}

//True or False

Speciation is the process of extinction of species. {F}

Geographical isolation leads to reproductive isolation. {T}

Darwin’s finches are an example of adaptive radiation. {T}

Genetic drift occurs only in large populations. {F}

Sympatric speciation occurs without geographical isolation. {T}

Mutation is not a factor in speciation. {F}

Behavioral isolation can lead to reproductive isolation. {T}

Speciation is a slow process that occurs over generations. {T}

Gene flow promotes speciation. {F}

Allopatric speciation occurs due to geographical barriers. {T}

//Fill in the blanks

Speciation refers to the formation of ______ species.
{
  = New
  ~ Old
}

______ isolation is a key factor in allopatric speciation.
{
  = Geographical
  ~ Behavioral
}

Genetic drift occurs due to ______ in small populations.
{
  = Chance
  ~ Selection
}

______ radiation is the process where organisms diversify rapidly into new forms.
{
  = Adaptive
  ~ Artificial
}

Darwin’s finches are an example of ______ speciation.
{
  = Allopatric
  ~ Sympatric
}

Reproductive isolation prevents ______ between populations.
{
  = Gene flow
  ~ Mutation
}

Sympatric speciation occurs without ______ isolation.
{
  = Geographical
  ~ Genetic
}

Mutation introduces ______ in a population.
{
  = Genetic variation
  ~ Isolation
}

Speciation due to differences in mating behavior is called ______ isolation.
{
  = Behavioral
  ~ Temporal
}

______ barriers can lead to reproductive isolation.
{
  = Physical
  ~ Chemical
}

//Numericals

If a population of 500 individuals is split into two groups of 250 each due to a geographical barrier, what percentage of the original population is isolated?
{
  = 50%
  ~ 25%
  ~ 75%
}

In a population, if the mutation rate is 1 in 10,000 per generation, how many mutations occur in 1 million individuals?
{
  ~ 10
  ~ 100
  = 1,000
}

If a species of bird is isolated into 3 groups, and each group evolves into a new species, how many species exist now?
{
  ~ 1
  ~ 3
  = 4
}

A population of 1000 individuals undergoes genetic drift. If 10% of the population is affected each generation, how many individuals are affected in 5 generations?
{
  = 500
  ~ 1000
  ~ 1500
}

If a mutation occurs in 2% of a population of 2000, how many individuals show the mutation?
{
  ~ 20
  = 40
  ~ 60
}

If two populations of 300 and 700 individuals are separated and evolve into distinct species, what is the total number of species?
{
  ~ 1
  = 2
  ~ 3
}

If 5% of a population of 10,000 migrates and forms a new population, how many individuals are in the new population?
{
  = 500
  ~ 1000
  ~ 200
}

A species of fish is isolated into 4 groups due to a river splitting. If each group evolves into 2 new species, how many species exist now?
{
  ~ 4
  ~ 8
  = 12
}

If a population of 1000 individuals has 2% undergoing mutation every generation, how many individuals show mutations after 3 generations?
{
  ~ 60
  ~ 120
  = 180
}

If a population splits into 3 groups due to geographical isolation and only 2 groups evolve into new species, how many species are there now?
{
  ~ 3
  = 4
  ~ 5
}

//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
= Allopatric speciation -> Geographical isolation 
= Sympatric speciation -> No geographical isolation 
= Adaptive radiation ->Diversification into new forms
= Genetic drift -> Random changes in gene pool
}


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