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VICBiologyQuick questions
Unit 4: How does life change and respond to challenges?
Quick questions on Speciation (allopatric, sympatric, reproductive isolation): VCE Biology Unit 4
10short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is the biological species concept?Show answer
A biological species is a group of organisms whose members can interbreed in nature to produce viable, fertile offspring, and which are reproductively isolated from other such groups.
What is allopatric speciation?Show answer
Allopatric speciation (allo = other, patric = place) occurs when a population is split by a geographical barrier.
What is sympatric speciation?Show answer
Sympatric speciation (sym = same) occurs within the same geographical area, without a physical barrier. It is less common but well documented in some groups.
What is reproductive isolating mechanisms?Show answer
Once two populations stop interbreeding, reproductive isolating mechanisms maintain the separation. They are grouped by when they act, relative to fertilisation.
What is examples?Show answer
Kaibab and Abert's squirrels on opposite rims of the Grand Canyon; Galapagos finches diverging from a single colonising population; Australian marsupials diverging from the rest of Pangaean placentals after continental drift.
What is saying speciation happens "to an individual"?Show answer
Speciation is a population-level process. Individuals do not speciate.
What is confusing reproductive isolation with geographical isolation?Show answer
Geographical isolation is one cause; reproductive isolation is the outcome that defines a new species.
What is saying postzygotic mechanisms "prevent fertilisation"?Show answer
They do not. They allow fertilisation but disadvantage the hybrid.
What is calling polyploidy "rare"?Show answer
It is uncommon in animals but very common in plants and is responsible for many crop species.
What is forgetting that the biological species concept fails for some groups?Show answer
It works for sexually reproducing animals; it cannot be applied to asexual or fossil species.