selection and populations

Question 1

Natural
selection

Answer 1

• the process that leads to
  evolution in populations
• results in species becoming
  better adapted to their
  environment

Question 2

Selection
pressure

Answer 2

• factors that affect the survival
  of an organism
• the driving force of natural
  selection

Question 3

Differential
reproductive
success

Answer 3

• not all individuals are equally
  likely to reproduce
• results in changes in allele
  frequencies within a gene pool

Question 4

Allele
frequency

Answer 4

The proportion of an allele for a
gene the population

Question 5

Disruptive
selection

Answer 5

• Individuals with either extreme
  trait are more likely to survive
  and pass on their alleles
• the middling trait allele
  becomes less frequent
• leads to speciation

Question 6

Reproductively
isolated

Answer 6

• Two populations of the same
  species, but they cannot breed
  together
• there is no gene flow

Question 7

Speciation

Answer 7

the process that results in the
creation of new species

Question 8

Allopatric
speciation

Answer 8

• Two populations become
  reproductively isolated due to
  being geographically separated
• results in the formation of two
  new species.

Question 9

Sympatric
speciation

Answer 9

• The formation of new species without
  geographical isolation
• Occurs when reproductive isolation
  arises within the same population in
  the same area
• → e.g. due to behavioural changes,
  different mating times, or mutations
• Leads to no gene flow between groups,
  resulting in the formation of two
  distinct species

Question 10

Genetic drift

Answer 10

• the random change in
  allele frequencies in a
  population over
  generations
• has greater effect in small
  populations
• substantial genetic drift
  results in evolution

Question 11

Population

Answer 11

• A group of organisms of the
  same species
• occupying a particular space at
  a particular time
• that can potentially interbreed.