Reproductive Isolation and Speciation
Biology Essentials- Reproductive Isolation and Speciation Guided
Viewing Worksheet
Name:
_______________________________________________________
1: What happened with Diane Dodd and the fruit flies? How did she create reproductive
isolation?
She took a group of fruit flies and feed them different things and after 8 generations the different species created reproductive isolation.
2: What is the definition a species?
A group of organisms that can inter breed and produce fertile off springs.
3: What are the two main types of
barriers in reproductive isolation?
Geographic isolation
Post-zygotic isolation
4: What is gene flow? What is reproductive isolation?
Genes flow is when genes are mixed within a population to create species and reproductive isolation is when species don't have gene flow
5: What is geographic isolation? (Give an example).
When there's an isolation due to whrere they exist
6: What is allopatric
speciation? (give an
example)
when there are two groups in different lands, example meadowlarks
7: What is sympatric
speciation? (give an
example)
when species live in the same land, example plant chrmosomes
8: What is peripatric/parapatric
speciation? (give an
example)
When the difference in species is their DNA example African and Indian elephants
9: What are pre-zygotic
barriers? Name the types of
pre-zygotic barriers (explain each).(Temporal, Mechanical, Behavioral)
Barriers that occurs before zygote forms
Temporal: Breed at different time of the year
Mechanical: Their sex parts are in different places
Behavior: Different behavior for different species
10: What are post-zygotic barriers?
Name the types of post-zygotic barriers- give examples.(Zygote Mortality, Hybrid Sterility)
Barriers occurred after zygote is formed
zygote mortality: when zygote is formed but then immediately dies
Hybrid sterility: can't produce more off springs
11: What is polyploidy? What happens? Where is this common?
Is a mistake in chromosomes which leads to not breeding and it's common in plants
12: What is the theory of Punctuated Equilibrium?
A theory that says speciation doesn't occur gradually over time, it occurs very quickly.