Homologous Structures and Index Fossils MS-LS4-1 & MS-LS4-2

Front

What are homologous structures?

Back

Structures that are inherited from a common ancestor, showing similar anatomy despite different functions.

Front

True or False: Homologous structures indicate a common ancestry among organisms.

Back

True

Front

What do organisms that share a more recent common ancestor have in common?

Back

They share more similarities in anatomy.

Front

What are analogous structures?

Back

Structures that serve similar functions but do not share a common ancestor.

Front

What are vestigial structures?

Back

Structures that have lost their original function through evolution.

Front

What is the significance of mutations in evolution?

Back

Mutations bring about genetic variation needed for a population to change over time.

Front

What is an example of homologous structures?

Back

The forelimbs of humans, whales, and bats.

Front

What is the difference between homologous and analogous structures?

Back

Homologous structures arise from a common ancestor, while analogous structures arise independently.

Front

What is the role of index fossils in geology?

Back

Index fossils are used to identify and date the layers of rock in which they are found.

Front

What characteristics make a good index fossil?

Back

A good index fossil is widespread, abundant, and existed for a short geological time.