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VICBiologyQuick questions
Unit 4: How does life change and respond to challenges over time?
Quick questions on Speciation (allopatric, sympatric, reproductive isolation): VCE Biology Unit 4
8short 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 are 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 are 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 q1?Show answer
Distinguish allopatric from sympatric speciation, and identify the key driver of each. [2 marks]
What is q2?Show answer
Classify each as a prezygotic or postzygotic isolating mechanism: (a) different mating seasons, (b) sterile hybrid offspring, (c) incompatible genitalia, (d) hybrid inviability before birth. [2 marks]
What is q3?Show answer
Refer to Australian rosellas. (a) State the biological species concept. (b) Explain how the ice age contributed to speciation.