The relative age of a rock is _____.

its age compared to the ages of other rocks

Many scientists hypothesize that the dinosaurs became extinct because _____.

an asteroid hit earth, throwing dust into the atmosphere

How do most fossils form?

Living things die and their remains are buried by sediments.

the preserved remains or traces of remains of an organism

The evolution of photosynthetic organisms about 2.5 billion years ago led to _____.

an increase in oxygen in the atmosphere

Radioactive decay occurs when atoms of an unstable element _____.

break down to form atoms of another element

The geologic time scale is a record of _____.

the life forms and geologic events in Earth’s history

The law of superposition states that, horizontal layers of sedimentary rock, each layer is __ .

older than the layer above and younger than the layer below

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Geologic Time Scale

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#Geologic time

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Questions 18

Answers

1
The relative age of a rock is _____.
less than the age of the fossils the rock contains
its age compared to the ages of other rocks
its age based on how much carbon-14 the rock contains
the number of years since the rock formed
2
A fossil formed when minerals replace all or part of an organism is called a _____.
petrified fossil
trace fossil
cast
mold
3
The end of the Paleozoic was marked by the _____.
extinction of the dinosaurs
evolution of winged insects
Permian extinction
evolution of plants
4
Many scientists hypothesize that the dinosaurs became extinct because _____.
competition with mammals led to the extinction
Pangaea caused climate change
a series of diseases wiped out plant-eating dinosaurs
an asteroid hit earth, throwing dust into the atmosphere
5
How do most fossils form?
Living things die and their remains are buried by sediments.
Freezing preserves the remains of an organism.
The soft parts of an organism change to stone.
The hard parts of an organism dry out in the air.
6
The process by which all the different kinds of living things change over time is called _____.
evolution
deposition
replacement
sedimentation
7
A fossil is ____.
the preserved remains or traces of remains of an organism
any dead organism
a perfect copy of a rock
an unusual type of rock
8
The evolution of photosynthetic organisms about 2.5 billion years ago led to _____.
the first mass extinction
the Precambrian Explosion
an increase in the UV radiation reaching Earth’s surface
an increase in oxygen in the atmosphere
9
The earliest life forms were _____.
fossils
single-celled organisms
vertebrates
dinosaurs
10
Radioactive decay occurs when atoms of an unstable element _____.
become part of a fossil
are exposed to chemical weathering
join with atoms of another element
break down to form atoms of another element
11
The Paleozoic, Mesozoic, and Cenozoic are divisions in the geologic time scale called _____.
eras
centuries
periods
layers
12
The geologic time scale is a record of _____.
the life forms and geologic events in Earth’s history
the thickness of sedimentary rock layers
the rate of fossil formation
the time since the evolution of dinosaurs
13
The first vertebrates were _____.
reptiles
lungfishes
amphibians
jawless fishes
14
The fossils of organisms widely distributed but only lived during a short time are called ____.
petrified fossils
index fossils
carbon film fossils
trace fossils
15
Radioactive dating enables geologists to determine _____.
the absolute ages of rocks
the half-life of a fossil organism
the age of the atoms in a rock
the relative ages of rocks
16
A type of organism that no longer exists on Earth is said to be _____.
sedimentary
fossilized
extinct
petrified
17
____ can provide clues about the activities of ancient organisms.
Trace fossils
Remains preserved in amber
Molds and casts
Carbon films
18
The law of superposition states that, horizontal layers of sedimentary rock, each layer is __ .
neither older nor younger than the other layers
older than the layer above and younger than the layer below
younger than the layer above and older than the layer below
always older than any vertical layers

Geologic Time Scale Flashcards | StudBud