Worksheetsselection and speciation
Total questions: 20
Worksheet time: 12mins
When a species environment favors one dominant type of characteristic to the point that the other variations of the trait start to disappear is called _____.
disruptive selection
directional selection
stabilizing selection
unstabilizing selection
All the genes in a population are the population’s
Gene flow
Gene pool
Genotype
Fitness
Which of the following is the best definition of species?
A group of organisms that lives in the same habitat
A group o organisms that exploit the same ecological niche
A group of organisms that can interbreed and produce viable and fertile offspring
A group of organisms that have the same appearance
Sparrows with average sized wings survive severe storms better than those with longer or shorter wings, illustrating
Sexual selection
Directional selection
Disruptive selection
Stabilizing selection
The process of a new species arising within the geographic range of the parent population is called
ecological speciation
allopatric speciation
adaptive radiation
sympatric speciation
Which of the following must occur after a period of geographic isolation in order for the two sibling species to remain genetically distinct following their geographic reunion in the same home range?
Prezygotic barriers
Postzygotic barriers
Ecological isolation
Reproductive isolation
Only a few types of a particular bird species diverge after a small number colonises a new island. This mechanism is called
stabilizing selection
directional selection
the founder effect
disruptive selection
All of the following examples describes prezygotic isolating mechanisms except
elaborate and unique courtship display to identify mates
reproductive organs that are physically incompatible
hybrids that are viable but sterile
different breeding times
1. When phenotypes are favoured at both extreme of a normal distribution curve, _____________ selection.
directional selection
normal selection
stabilizing
disruptive
3. A flock of birds migrate to an island where the only food can be found are hard shell nuts. What will happen to the birds ?
I. Birds with large and strong beak will survive
II. Birds with thin and long beak will leave
III. Birds with large and strong beak will leave
I only
I and II
II and III
I, II and III
Migration of breeding individuals between population causes movement of alleles which refer to as
gene flow
mutation
genetic drift
natural selection
The introduction of a small population onto an island results in limited gene pool for the population is an example of
genetic drift
bottleneck effect
founder principle
Mendel law
Prevention of genetic exchange between two species because they reproduce at different time of the day, season or year is called
sexual isolation
habitat isolation
ecological isolation
temporal isolation
Hybrid breakdown is characterized by
fertility of the hybrid.
sterility of the progeny
death of the hybrid during pregnancy
early death of progeny
Over the years, white mice became extinct and darker mice survived. This is
stabilizing selection
directional selection
disruptive selection
due to exercise
Which of the following best illustrates natural selection?
An organism with favorable genetic variations will tend to survive and breed successfully.
A population monopolizes all of the resources in its habitat, forcing other species to migrate.
A community whose members work together utilizing all existing resources and migratory routes
The largest organisms in a species receive the only breeding opportunities.
