19.1 The Fossil Record Answers

Dinosaurs appeared before answer choices A mammals B photosynthesis C chordates D land plants

A Mammals

Fill out the flowchart to explain how fossils are formed

1st blank: Sediments settle to the bottom of a body of water 2nd blank: Fossils sink to the bottom and more sediments pile on top of the fossil

A species that is easily recognizable, existed for a relatively short period of time, and covered a wide geographic area may be used as a(n) Answer choices A.Index fossil B.Fossil record C.Microfossil D.Macrofossil

A. Index Fossil

Which of the following appeared on Earth most recently? Answer choices: A chordates B tetrapods C dinosaurs D single celled algae

B. tetrapods

The same index fossil is found in rock layers A and B that are separated by several miles. What can you infer about the relationship between the rock layers? ANSWER CHOICES: A. Layer A is older than B B. The sediments in layer B were deposited before those in layer A C. Layers A and B are probably about the same age D. Layer B contains more radioactive isotopes than layer A

D. Layer B probably contains more radioactive isotopes than layer A

Species that died out are said to be ________

Extinct

Fossil A is found in a layer of rock above a layer containing Fossils B. Which fossil is probably older? Explain your reasoning.

Fossil B, because it is in deeper meaning that it had probably formed earlier than Fossil A

What information does the fossil record provide?

History of life on earth. It shows how different organisms including species and how they have changed over time.

What is an Index fossil? What do index fossils reveal about other materials found with them?

Index fossils are distinctive species that have lived for a short period of time but over a wide area. They reveal relative ages of rock layer and their fossil

How might an asteroid impact Earth's climate?

It depends on how violent the impact is. If it is very violent it can kick enough dust and debris into the atmosphere to cause or contribute to world wide extinction of an organism on land and into the water.

How do scientists calculate the age of a sample using radiometric dating?

Measure the ratio of radioactive atoms to decayed atoms & calculate how many half-lifes have passed.

Scientist who study fossils are called __________

Palentologist

The first three questions have a missing word in the sentence and it will be shown as a blank in the term spot

Read below

Most fossils are found in layers of ___________ rock?

Sedimentary

What is a fossil record

The fossil record is records of all the fossils that have been found to present date

Explain the theory of plate tectonics and tell how it has affected the distribution of fossils and organisms.

This theory that the earth's outermost layer divided. The movement is called a continental drift. Since the continent moves everything in and under the continent moves including fossils

What is a half-life?

Time required for half of the radioactive atoms of samples to decay.

Fill in the missing eras and Periods in the geologic time scale below.

Time, Period, Era 1.8-Present Quaternary Cenozoic 23-1.8 Neogene Cenozoic 65.5-23 Paleogene Cenozoic 146-65.6 Cretaceous Mesozoic 200-146 Jurassic Mesozoic 251-200 Triassic Mesozoic 299-251 Permian Paleozoic 359-299 Carboniferous Paleozoic 416-359 Devonian Paleozoic 444-416 Silurian Paleozoic 488-444 Ordovician Paleozoic 542-488 Cambrian Paleozoic 4600-542 Precambrian time Preterozoc