Ch. 13 Review-Earth’s History
1. Which era spans the least amount of time on the geologic scale?
a. Cenozoic
c. Paleozoic
b. Mesozoic
d. Precambrian
2. The most common Precambrian fossils are
a. Fish
c. Trilobites
b. Stromatolites
d. Ferns
3. Which era is known as the “age of reptiles”?
a. Cenozoic
c. Paleozoic
b. Mesozoic
d. Proterozoic
4. Modern squids descended from what type of early Paleozoic organisms?
a. Cephalopods
c. Brachiopods
b. Trilobites
d. Amphibians
5. Jawless fishes that evolved during the Devonian period were
a. Prokaryotes
c. Vertebrates
b. Amphibians
d. Invertebrates
6. Which adaptation allowed gymnosperm plants to out-compete spore-bearing plants?
a. Stems
c. Leaves
b. Seeds
d. Roots
7. Reptiles that were adapted to fly included the
a. Plesiosaurs
c. Ichthyosaurs
b. Pterosaurs
d. Tyrannosaurs
8. Humans first appeared during the
a. Cretaceous period
c. Quaternary period
b. Jurassic period
d. Tertiary period
9. Insulating body hair is a characteristic of
a. Mammals
c. Reptiles
b. Amphibians
d. Invertebrates
10. What development caused the emergence of animals that were grazing herbivores?
a. Seed plants
c. Fruits
b. Grasses
d. Carnivorous mammals
11. How did plants help change Earth’s early atmosphere? Primitive plants used photosynthesis and
released oxygen. Plants dramatically changed the makeup of Earth’s atmosphere by using carbon
dioxide and releasing oxygen. The oxygen content of Earth’s atmosphere increased.
12. What are shields? Shields are areas of Precambrian rock that reach the surface.
a. What kind of information is gained from shields? Metal ores from shields provide information
about Precambrian time.
13. The photograph on pg. 389 shows evidence of what kind of organism? Cyanobacteria (stromatolites)
14. What significant tectonic activity occurred during the Mesozoic? Pangaea broke up
15. What present-day continents made up Gondwana?
a. South America
b. Africa
c. Australia
d. Antarctica
e. India
f. China
16. To which large group of animals do trilobites belong? Invertebrates/arthropods
17. Modern fishes and sharks both evolved from what type of ancient animals? Jawless/Armor-plated fishes
18. What development allowed mammals to adapt to different environments successfully? Mammals are
warm-blooded, which allows them to inhabit colder regions and remain active at different seasons and
times of day.

Ch 13 Review KEY