X-Linked Recessive Trait

a. Usually more males than females are affected.

b. Affected sons are usually born to unaffected mothers; thus, the trait skips generations.

c. Approximately half of a carrier (heterozygous) mother’s sons are affected.

d. Never passed from father to son.

e. All daughters of affected fathers are carriers.

TLS Online TPP Program

#Id: 9575

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 9576

#Unit 11. Evolution and Behavior

Pre Cambrian- Earliest eukaryotes and multicellular eukaryotes. Oxygen levels increase

TLS Online TPP Program

#Id: 9577

#Unit 11. Evolution and Behavior

Cambrian - Most marine invertebrates. Ozone layer forms

TLS Online TPP Program

#Id: 9578

#Unit 11. Evolution and Behavior

Ordovician - Primitive plants and fungi colonize land, first jawless vertebrates,  Mass extinction at end of period

TLS Online TPP Program

#Id: 9579

#Unit 11. Evolution and Behavior

Silurian - Origin of jawed fishes and arthropods, Invasion of land by primitive land plants

TLS Online TPP Program

#Id: 9580

#Unit 11. Evolution and Behavior

Devonian - First amphibian and first seed plant appear, and insects Mass extinction late in period