What is sympatric speciation?

Sympatric speciation occurs when populations become reproductively isolated within the same geographical area through reproductive isolating mechanisms.

What is temporal isolation as a reproductive isolating mechanism?

Temporal isolation occurs when populations reproduce at different times (seasons, times of day), preventing interbreeding.

What is behavioural isolation as a reproductive isolating mechanism?

Behavioural isolation occurs when differences in courtship behaviour or mating rituals prevent interbreeding between populations.

What is mechanical isolation as a reproductive isolating mechanism?

Mechanical isolation occurs when physical differences in reproductive structures prevent successful mating between populations.

What is gametic isolation as a reproductive isolating mechanism?

Gametic isolation occurs when gametes from different populations are incompatible and cannot fuse successfully.

OCR A-Level Biology H420

Cell Structure

Topic overview Microscopy, slide preparation and staining Biological drawings, magnification and resolution Eukaryotic cell ultrastructure The secretory pathway and the cytoskeleton Prokaryotic and eukaryotic cells compared

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Patterns of Inheritance

Speciation and isolating mechanisms

1 thing to know
Components 02 and 03

Overview

Allopatric and sympatric speciation, and the temporal, behavioural, mechanical and gametic isolation that keeps populations from interbreeding.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

What is allopatric speciation?

Questions from this subtopic

Each one with the model answer underneath.

1
What is allopatric speciation?
Model answer
Allopatric speciation occurs when populations are separated by geographical barriers, preventing gene flow and allowing independent evolution.
2
What is sympatric speciation?
Model answer
Sympatric speciation occurs when populations become reproductively isolated within the same geographical area through reproductive isolating mechanisms.
3
What is temporal isolation as a reproductive isolating mechanism?
Model answer
Temporal isolation occurs when populations reproduce at different times (seasons, times of day), preventing interbreeding.
4
What is behavioural isolation as a reproductive isolating mechanism?
Model answer
Behavioural isolation occurs when differences in courtship behaviour or mating rituals prevent interbreeding between populations.
5
What is mechanical isolation as a reproductive isolating mechanism?
Model answer
Mechanical isolation occurs when physical differences in reproductive structures prevent successful mating between populations.
6
What is gametic isolation as a reproductive isolating mechanism?
Model answer
Gametic isolation occurs when gametes from different populations are incompatible and cannot fuse successfully.

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