UNDERSTANDING SEQUENCE
1. Read FORMATION OF THE EARTH on pages 257258, which describes one hypothesis about how life began on Earth. After you complete the section, read the following events. Then number them in the order in which they occurred.
As you work, look for clues to the sequence of events, such as signal words and phrases and references of eras or years.
a. ____ After the planet's formation, frequent and violent volcanic eruptions shaped the land forms.
b. ____ This pressure generated heat that melted the core material of the young planet.
c. ____ 6 billion years ago, the solar system formed from swirling gases and dust.
d. ____ Finally, rainwater flowed from the land into basins in the Earth's crust, forming seas.
e. ____ Hydrogen, the lightest of materials, probably formed the outermost layer, which became Earth's first atmosphere.
f. ____ When the heavier elements such as nickel and iron settled to the center, they formed the planet's core.
g. ____ Next, gravity compressed Earth's basic materials, producing intense pressure.
h. ____ These volcanic eruptions emitted gases into the changing atmosphere.
i. ____ 4.1 billion years ago, the lighter materials such as hydrogen and helium rose to the surface and cooled to a solid crust.
j. ____ 4.5 billion years ago, held by the gravity of the sun, pockets of dust and rocks condensed to become planets, comets, and asteroids.
2. List the clues that you used to find the correct sequence of events above.
a. signal words and phrases [2 wol]
b. time references [2 wol]
3. Study Figure 11.17 on pages 269273. Then answer the following questions.
a. Which developed first: marine reptiles or land plants? [1 wol]
b. During what era did Eukaryotic organisms evolve? [1 wol]
c. Which creatures evolved later: large mammals or birds? [1 wol]
d. What creature evolved between the first mammals and birds? [1 wol]
e. Arrange the following creatures in the order in which they evolved: modern humans, vertebrates, mammals, reptiles. [1 wol]
f. According to the time line, which is older: large mammals or shelled invertebrates? [1 wol]
g. During what period did land plants evolve? [1 wol]
h. Arrange the following geological periods in chronological order: Triassic, Quaternary, Devonian, Cambrian, Cretaceous [1 wol]
i. Did Cretaceous creatures die out before or after flowering plants flourished? [1 wol]
j. Which period took place directly after the Permian period? [1 wol]
k. List 5 groups of organisms that developed before the Permian period. [2 wol]
l. List 5 groups of organisms that developed after the Permian period. [2 wol]
Click here to check your answers.
Reading Strategy 3.1 | Worksheet 3.1
Reading Strategy 3.2 | Worksheet 3.2
SUPER READ! home page
Copyright © 2008 by Pearson Education, Inc. publishing as Pearson Prentice Hall. All rights reserved.
Privacy Statement, Terms of Use, Permissions