In the Geologic Timescale,an Environmental Condition That Changed Prior to the Appearance

question 39

Multiple Choice

In the geologic timescale,an environmental condition that changed prior to the appearance of complex species,from eukaryote cells to animals and plants,was

• A) an "explosion" of simpler and diverse animals that helped develop ecological interrelationships among species.
• B) a large increase in atmospheric oxygen gas levels from photosynthesis in prokaryote cells.
• C) microevolution had to change the species traits enough that paleontologists could distinguish the geologic eras and periods.
• D) non-vascular and vascular plants had to develop the photosynthesis process and produce oxygen gas in the atmosphere.

---

Definitions:

Melting Pot

A metaphor for a society where many different types of people blend together as one, often used to describe the United States.

Settler Societies

Societies historically established by settlers who colonized land, often displacing indigenous populations, including countries like the United States, Canada, Australia, and New Zealand.

Coolie Trade

The system of indentured labor that transported workers, mainly from India and China, to various colonies to work in plantations or construction projects during the 19th and early 20th centuries.

American West

A region in the United States characterized by its historical frontier period, exploration, and expansion during the 19th century.