Uplift and Formation of a Mountain Range Divides a Freshwater

question 10

Multiple Choice

Uplift and formation of a mountain range divides a freshwater snail species into two isolated populations.Erosion eventually lowers the mountain range and brings the two populations together again,but when they mate,the resulting hybrids all produce sterile young.This scenario is an example of

• A)sympatric speciation.
• B)diversifying speciation.
• C)incomplete speciation.
• D)allopatric speciation.

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Definitions:

Choanoflagellates

A group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of animals.

Ribbon Worms

A group of soft-bodied, often very long and slender invertebrates belonging to the phylum Nemertea.

Flatworms

A phylum of simple, bilaterally symmetrical, unsegmented invertebrates with a flattened body, including planarians, flukes, and tapeworms.

Acoelomates

Animals without a coelom, or body cavity, between the digestive tract and the outer body wall, including flatworms.