I. Multiple choice: Write the correct letter on the space provided.

___C____1. Geologic time encompasses all time since

a. the formation of the universe.
b. the formation of the solar system.
c. the formation of Earth.
d. the formation of life.
___D___2. Order the divisions of geological time from the longest to the shortest.
a. epochs, periods, eras, eons
b. eons, epochs, eras, periods
c. periods, epochs, eras, eons
d. eons, eras, periods, epochs
___A____3. Geologic eras are largely determined by .
a. Earth's orbital position.
b. shifts in the fossil record.
c. average global temperatures.
d. distribution of rock sequences.
___D____4. Which of the following is the correct order of the three recent geologic eras from
oldest to the most recent?
a. Mesozoic, Paleozoic, Cenozoic
b. Paleozoic, Cenozoic, Mesozoic
c. Mesozoic, Cenozoic, Paleozoic
d. Paleozoic, Mesozoic, Cenozoic
____D___5. Which is the earliest division of time on the geological time scale?
a. Hadean
b. Archean
c. Quaternary
d. Phanerozoic
___C____6. The Archean Eon ranges from approximately billion years ago.
a. 0.5 - 0.1
b. 2.5 - 0.5
c. 4.0 - 2.5
d. 4.5 - 4.0
____D___7. In which geologic era do we currently live?
a. Proterozoic
b. Paleozoic
c. Mesozoic
 d. Cenozoic
____A___8. Which was the largest mass extinction event, killing over 90% of all species?
a. Permian–Triassic
b. Ordovician–Silurian
c. Triassic–Jurassic
d. Cretaceous–Paleogene
___C____9. Trilobites and other early arthropods first appeared during what geologic period?
a. Devonian
b. Eocene
c. Cambrian
d. Permian
___D____10. During which time did free oxygen begin to build-up in Earth's atmosphere?
a. Archean
b. Paleozoic
c. Mesozoic
d. Proterozoic

II. Based from your understanding, answer the following questions. (5 pts each)

1. What was Pangaea? What evidence supports the past existence of Pangaea?
 Pangea is a supercontinent which was surrounded by a single ocean called Panthalassa. Some
of the evidences shows that there were identical species, like the extinct see fern that have
been discovered in the fossil record on now widely separated continents.

2. Describe the theory of continental drift and identify who first proposed this theory.
 The theory of continental drift was proposed by Alfred Wegener, it explains how continents
move about on the surface of the Earth. It introduced the concept of continents shifting to
geoscience

3. How did the theory of plate tectonics improve on the theory of continental drift?
 While the theory of plate tectonics explain the reason as to why the Earth’s continent are
moving, it improves Wegener’s theory of continental drift of which is it was used to be a one
continent.
 4. Explain the relationships among eons, eras, epochs, and periods of the geologic time scale.
 Eons is the largest span of time in the geological time scale, divided by major divisions called
eras, which is the long division of the geological time. It is then divided into periods, it is the
major subdivision of the era, Lastly, the periods are then divided into epochs, it is the
subdivision of the periods.

5. How did scientists account for fossils and other geological evidence as they developed the
geologic time scale?
 The scientists relates the subdivisions of the geological time with events that happened in
the past, they studied the rocks and other any evidences of fossils, leaves, shells that they
could find from the past life of the Earth. They observed, each and every fossils and their
changes from oldest to youngest rocks. With this, they are able to develop the geological
time scale.

III. The following are the different eras that explained the origin of life on earth, give
important events on each eras and answer the following questions that follows.

Precambrian Era – TIME PERIOD

Three Events
A solar systems was formed within a cloud of dusts and gas which eventually creates asteroids, comets, moons,
and planets.
The Earth soon received enough mass to, it began to form a continental landmass such as water from comets
condensed in the atmosphere and fell as a rain which cooled down the Earth and oceans are formed from it.
The plate tectonics starts to process, and cells began to live from the environment due to energy conversion.
Roughly, when did the Cambrian explosion begin and what occurred that was different than the Precambrian
explosion?
 The explosion began at about 500 million years ago, there were major changes that occurred including the
fossils and animal species were burrowed starts appearing and it was the evolution of reefs.
What happened during the Cambrian explosion? How is that important to evolution?
 The Cambrian explosion only happened in a short time and resulted in divergence of the animals. This is
important to the evolution as it is one of the strongest evidences of the past events on Earth.

Define the term “fossil record” and explain how viable fossils are formed.
 The fossil record is a collections of fossils, evidences of animal species that are preserved, it is the
evidences that showed that there was once life on Earth in the past. Fossils are formed when a plant or
animal dies in a environment that is surrounded by water and would get buried by mud and silt, this will
help the tissues to decompose and leave the remains of bones behind and the as time goes by some
sediments builds over and hardens what we now call “fossils”

What are some of the reasons scientist believe new life forms evolved in abundance during the Cambrian
period.
 Due to the Cambrian Explosion, scientists were able to believe that there new life forms to the diversity of
life that emerged.
 Paleozoic Era- TIME PERIOD
Three Events
It began after the Cambrian explosion where the extensive evolution of life began to bloom in the planet.
Rocks, mountains, and major continentals were formed.
The large mass extinction of animals by the end of the era.
How old was Earth when life first began? What were the first life forms?
 4.5 billion years ago, the first life forms were bacteria and microbes.

What happened during the Precambrian explosion? How is that important to evolution?
 There were major changes in the diversity of the fossils, it is important to the evolution for the evidence
that were revealed in this era supports the theory of scientists that there was life on earth.

Describe Earth’s early atmosphere? How did it change?

 The atmosphere was once filled with carbon dioxide, and as the earth cooled and was covered with
volcanoes, the gases from the volcanoes began to affect the atmospehere.

Mesozoic Era- TIME PERIOD

Three
Events
Dinosaurs began to live in this era, and other animals such as birds and other mammals.
Plants began to bloom, like the flowering plants etc.
A mass extinction occurred that killed dinosaurs though many of animals and plants lived.
How do you think Pangaea breaking apart contributed to evolution?
 The contribution of Pangea breaking apart caused the animals or the specieis to be separated from each
continents by the seas and oceans. This helped in creating new species and the new climates to evolve.
Describe the plant and animal life during the Mesozoic life?
 Some plants are conifers, some trees and shrubs, seed ferns and by the end of the era, flowering plants
evolved. The animals that lived in the era were carnivores, herbivores of dinosaurs.
What major evolutionary change occurred for plants during this time period?
 The plants in the time period were ferns, conifers that helps the mammals to eat from, by the end of the
era flowering and fruiting plants evolves which has seeds ready to grow.

Many of life’s failures are people who did not realize how close they were to
success when they gave up. – Thomas Edison