Chapter 4. Geologic time, trilobite, index fossils

____ is a process by which organisms with characteristics suited to the environment will survive and reproduce.

The end of the Paleozoic Era was signaled by ____.

t/f: Charles Darwin proposed the theory of natural selectio

t/f: The Mesozoic Era means the era of middle life.

If a species can adapt to a changing environment, or ____, its descendants will survive.

t/f: The exoskeleton of a trilobite consists of four lobes or sections.

Plate tectonics may affect organic evolution because movement of plates may cause a change in ____.

t/f: When Pangaea separated it broke into two large land masses known as Eurasia and Australioland.

Periods are divides into groups known as as _______________.

t/f:Precambrian time contained 3 eons, the Hadean, the Archean, and the Proterozoic

The division of Earth's history into smaller units makes up the ____.

t/f: The Cenozoic Era means era of recent life.

t/f: The Cenozoic Era is divided into three periods.

t/f:The Alps and Andes formed during the Cenozoic Era.

____ on the geologic time scale are marked by major, striking, and worldwide changes in the type of fossils present.

The Alps, Andes, and Himalaya formed in the ____.

t/f: Cyanobacterai are blue-green algae thought to be one of the earliest forms of life on Earth.

This supercontinent formed at the end of the ____________________ Era.

t/f: The Palezoic Era means the era of recent life.

Reptiles evolved from an ancestor of amphibians that developed a(n) ____.

Trilobites are considered to be _______________ because they lived in vast regions of the world during specific periods of geologic time.

Life-forms that existed during the Paleozoic Era included ____.

The ____ formed during the Paleozoic Era.

____________________ was the supercontinent shown in Figure 14-

The change in a species over time is known as _______________.

Scientists believe dinosaurs evolved from ____ during the Mesozoic Era.

Today, some scientists think that ____.

t/f: Birds first appeared during the Jurassic Period.

t/f: The Himalaya moutains formed when Australia collided with India.

A life-form in the Precambrian time was ____

Little is known about much of Earth's early history because ____

Animal life in the Cenozoic Era includes ____.

Dinosaurs are thought to have been protective of their young because ____.

t/f: The present day period is the Quaternary Period and it began about 1.8 million years ago.

t/f: The super continent Panaea formed at the beginning of the Paleozoic Era.

____ existed during the Mesozoic Era.

The development of ____ factored in the development of complex organisms.

Eons are divided into groups known as _______________

t/f: Angiosperms are flowering plants that produce seeds with no outer covering.

Changes in the environment result in ____.

The hard scales of reptiles' skin helped them to retain water, enabling them to adapt to the ____ climate during the Mesozoic Era.

Humans first appeared during the ____ Era.

A life-form that evolved during the ____ Era was the dinosaur.

The longest subdivision in geologic time is a(n) ____.

t/f: The Appalachain Mountains were formed during the Paleozoic Era.

t/f: The Tertiary Period started 65 million years ago and continues through today.

Eras are divided into groups known as _______________.

Cenozoic Era life-forms include ____.

A(n) ____________________ is a group of organisms that only reproduces with other members of their group.

Only epochs in the ____ Era(s) have been given specific names.

t/f: Gymnosperms are plants that produce seeds but not flowers.

Changes in the trilobite exoskeleton can be attributed to ____.

t/f: The end of the Paleozoic Era was marked by the extinction of 90% of all marine life and 70% of all land species.

The longest subdivision of geologic time is are _______________.

Mammals first appeared in the ____________________ Period.

Animal life in the Paleozoic Era included all of the following EXCEPT ____.

Homo sapiens probably appeared ____ ago.

Angiosperms are the dominant land plant today because they developed ____.

Pangaea separated into ____.

t/f:Mammals first appeared during the Ordivician Period.

The division of Earth's history makes up the ________________.

The change in environments that may have occurred at the end of the Paleozoic Era may have been caused by ____.

t/f: Homo sapiens were thought to first appear about 140,000 years ago.

Which trilobite characteristic did not change through time?

Trilobites are index fossils because they ____.

The Mesozoic Era ended about 65 million years ago.

Geologic time is divided into units based upon types of ____.