Topic 2 lesson 3 in science

What is the only organism that lived in the Precambrian time ?

• algae
• fungi
• dinosaurs
• unicellular organisms

What are examples of organisms that were at the end of the Precambrian time ?

The first period of the Paleozoic era is know as................................, with many different kinds of organisms that had evolved.

• Cambrian
• Jurassic
• Triassic
• Devonian

A new event happened and it was called the Cambrian explosion because ...............................................

• all species went extinct
• many new species appeared over a relatively short period of time
• the event lasted for millions of years
• only one new species emerged

Animals without backbones are called.............................

• spineless
• backless
• vertebrates
• invertebrates

What are the organisms that had been found in the Precambrian time, and the Cambrian period?

The first vertebrates evolved during the .................................. period.

• Jurassic
• Triassic
• Devonian
• Ordovician

................................. are animals with a backbone.

• Arthropods
• Exoskeletons
• Invertebrates
• Vertebrates

Plants grew abundantly during the ............................. period.

• Cretaceous
• Silurian

• Jurassic
• Devonian

The.......................... period is called the Age of Fish.

• Carboniferous
• Devonian

• Mesozoic
• Jurassic