Why Are Australian Mammals All Marsupial While Mammals on Other

question 36

Multiple Choice

Why are Australian mammals all marsupial while mammals on other continents are mostly placental?

• A) The marsupial anatomy is better adapted to the environments of Australia than is the anatomy of placental mammals.
• B) The placental anatomy is better adapted to the environments of North and South America than is the anatomy of marsupial mammals.
• C) When the continents separated from one another, marsupials on Australia did not have the placental competitors that were present in the Americas.
• D) Marsupials outcompeted the placental mammals in Australia.
• E) Australian mammals have a different common ancestor than mammals elsewhere in the world. When the continents separated from one another through continental drift, marsupials on Australia did not have the placental competitors that were present in the Americas. The mix of plants and animals determine the course of evolution.

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Definitions:

Wernicke's Area

A region in the brain's temporal lobe involved in understanding spoken language and semantic processing.

Process

A series of actions or steps taken in order to achieve a particular end.

White Matter

Tissue in the brain and spinal cord made up of nerve fibers that connect different parts of the nervous system, important for efficient communication between neurons.

Gray Matter

A region of the brain and spinal cord consisting mainly of neuronal cell bodies and lacking myelinated axons, associated with processing and cognition.