Amplify Homologous Structures

This fossil snake and this living rat both have a structure in their skull called the quadrate bone. What best explains why both species have a quadrate bone?

• The snake and rat are different species, so they must not be related. They inherited the quadrate bone structure from separate ancestor populations.

• All species have their own specific body structures, so it is a coincidence that the snake and rat each happen to have the quadrate bone structure.

• The snake and rat both share the same ancestor population that had a quadrate bone. They inherited this structure from the ancestor population.

• is impossible to say. Fossils are very old; therefore, we cannot make observations of the snake’s ancestors, and we cannot explain its body structures.

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

Some organisms that share a common ancestor have features that have different functions, but similar structures.  These are known as

• vestigial structures

• analogous structures

• homologous structures

• fossil structures

Tags

NGSS.MS-LS4-2

The structures shown are_________

• homologous

• heterologous

• analogous

• vestigial

Tags

NGSS.MS-LS4-2

a body structure in two or more species that features the same parts

• shared structure

• speciation

• species

• ancestor population

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NGSS.MS-LS4-2

The forelimbs of mammals have similar anatomy because these groups descended from a recent common ancestor. Their bone structure is an example of a(n) (a)   structure.

• vestigial

• analogous

• homologous

Tags

NGSS.MS-LS4-2

What is this an example of?

• vestigial structures

• embryology

• homologous structures

• fossil record

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NGSS.MS-LS4-2

Do you think the two species have a common ancestor?

• NO

• YES

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

NGSS.MS-LS4-3

What is an example of a shared body structure?

• the distal bones in a whale and the distal bones in a wolf

• the distal bones in a whale and the pelvis in a whale

• the distal bones in a whale and the pelvis in a wolf

• the pelvis in a wolf and the distal bones in a wolf

Tags

NGSS.MS-LS4-2

Structures that are inherited from a common ancestor are homologous.

• True

• False

Tags

NGSS.MS-LS4-2

Which species (H, I, or K) is the closest relative to Species J?

• Species H

• Species I

• Species K

• Neither

Tags

NGSS.MS-LS4-2

NGSS.MS-LS4-3