Name______Period___ Date______Score_____
BIOLOGYWORKSHEET CHAPTER 12 HISTORY OF LIFE ON EARTH - NOVAK
Ws Ch9HistoryOfLife 2-08.doc
Chapter 12 Section 1 – How Did Life Begin
1. How long ago did the Earth form? ______
2. When the Earth cooled, it formed a rocky ______.
3. What did the water vapor condense into? ______
4. Where do scientists think life first evolved? ______
5. Scientist think life has evolved over hundreds of ______of years?
6. Evidence of the age of the Earth can be found by measuring the age of ______.
7. ______is the estimation of the age of an object by measuring its content of certain radioactive isotopes.
8. How is an isotope of an element different than its element element?______
9. ______are unstable isotopes that break down and give off energy in the form of charged particles called ______. ______
10. What is this breakdown called? ______
11. ______is the time it takes for one half of a given amount of a radioisotope to decay.
12. By measuring the proportions of certain radioisotopes and their products of ______, scientists can compute how many half lives have passed since a rock was formed.
13. Most scientists think that life on Earth developed through ______chemical and physical processes.
14. It is thought that the path to the development of living things began when molecules of nonliving matter reacted during the first billion years of Earth’s history
15. These chemical reactions produced many different simple ______molecules.
16. These chemical reactions produced many different ______organic molecules.
17. Energized by the ______and ______heat, these simple molecules formed more complex molecules that eventually became the building blocks of the first cells.
18. The hypothesis that many of the organic molecules necessary for life can be made from molecules of ______matter has been tested and supported by results of lab experiments.
19. In the 1920s A. I. Oparin and J.B.S. Haldane suggest that the early ______contained large amounts of organic molecules.
20. What did this hypothesis become known as? ______
21. They also hypothesized the molecules formed spontaneously in chemical reactions activated by ______radiation, ______eruptions, and ______.
22. The early Earth’s atmosphere lacked ______making formation of organic molecules possible.
23. Name four common compounds in Earth’s early atmosphere NOT including water. ______
24. Today, high energy electrons are quickly soaked up by the oxygen in earth’s ______.
25. Oxygen atoms have a great “______” for such electrons.
26. But without oxygen, high- energy electrons would have been free to react with hydrogen-rich molecules, forming a variety of ______compounds.
27. In 1953, who tested the primordial soup model? ______
28. According to Figure 2, Miller-Urey heated ______in a flask.
29. According to Figure 2, Miller-Urey they then added water vapor and what other gases to the tubes? ______
30. According to Figure 2, Miller-Urey, stimulated lightning by providing a ______.
31. According to Figure 2, Miller-Urey, after the spark and the vapors had been condensed, what did they find in the beaker below? ______
32. These results support the hypothesis that some basic chemicals of ______could have formed ______under conditions like those in the experiment.
33. Recent discoveries have caused scientists to ______the Miller-Urey experiment.
34. Four billion years ago, Earth did not have a protective layer of ______gas.
35. Without ozone, ______radiation would have destroyed any ammonia or methane in the early atmosphere.
36. If these gases are absent from the Miller-Urey experiment, ______biological molecules are NOT made.
37. If the chemicals needed to form life were not in the atmosphere some scientists argue that the chemicals ere produced within ocean ______or ocean ______.
38. The correct answer has ______been determined yet.
39. In 1986, geophysicist Louis Lerman hypothesized the ______model of chemical origins.
40. ______, ______and other gases resulted from undersea volcanoes and were trapped in underwater bubbles.
41. The bubbles protected the methane and ammonia needed to make amino acids from ______.
42. Here, in bubbles where reactants would be concentrated, the chemical reactions would take place much faster than what? ______
43. Next, the bubbles rose to the surface and burst, releasing simple ______molecules into the air.
44. Once in the wind, these simple organic molecules were exposed to ultraviolet radiation which provided ______for further reactions
45. More ______organic molecules that formed fell into the ocean with rain, starting another cycle.
46. Thus, the molecules of life could have appeared more quickly than is accounted for by the ______alone.
47. Scientists ______about the details of the process that lead to the origin of life.
48. There are enormous differences between ______organic molecules and large organic molecules found in ______.
49. How did amino acids link to form ______?
50. How did nucleotides form the long chains of ______that store the instructions for making proteins?
51. In the lab, scientists have ______been able to make either ______or ______form spontaneously in water.
52. However, short chains of ______have been made to form on their own in water.
53. RNA is the nucleic acid that does what? ______
54. In The 1980s, Thomas Cech hypothesized that ______was the first self-replicating information-storage molecule.
55. RNA then catalyzed the assembly of the first ______.
56. What organic compound makes up the cell membrane? ______
57. Lipids tend to gather in ______.
58. Lipids tend to form ______in vinegar.
59. Certain lipids, when combined with other molecules, can form a tiny droplet whose surface resembles a ______.
60. Short chains of amino acids can gather into tiny droplets called ______.
61. Another type of droplet, called a ______is composed of molecules of different types, including linked amino acids and sugars.
62. Why do scientists think microspheres are important? ______
63. Microspheres could not be considered true cells unless they had the characteristic of ______things, including ______.
64. Scientists disagree about the origin of ______.
65. Many scientists agree that double-stranded DNA evolved after ______.
66. RNA “______” catalyzed the assembly of the earliest ______.
67. Many scientists also agree that some microspheres or similar structures containing RNA developed a means of transferring their characteristics to ______.
68. But researchers do not yet understand how DNA, RNA and hereditary mechanisms first ______.
Name______Period___ Date______Score_____
Chapter 12 Section 2 – The Evolution of Cellular Life
69. The best evidence we have of early life is the ______which is the preserved or mineralized remains of or imprint of an organism that lived long ago.
70. The oldest fossil comes from rock ______billion years old.
71. The oldest known fossil is that of ______.
72. Define prokaryote. ______
73. The first prokaryotes to show in the fossil record were ______
74. Cyanobacteria are ______prokaryotes.
75. Much of the first ______produced on the Earth was due to cyanobacteria which released it into the ocean water.
76. After hundreds of millions of years, the oxygen escaped into the ______.
77. How much oxygen is in the air today? ______
78. Eventually in the early history of the Earth, ______different groups of prokaryotes evolved.
79. ______are prokaryotes that contain a chemical called peptidoglycan in their cell walls.
80. Name two common activities of eubacteria. ______
81. ______are prokaryotes that lack peptidoglycan in their cell walls and have unique lipids in their cell membranes.
82. Archaebacteria and eubacteria ______very early according to chemical evidence.
83. When did the first eukaryotes appear? ______
84. Which is larger a prokaryotic or a eukaryotic cell? ______
85. Which has the DNA enclosed in a nucleus, prokaryotic or eukaryotic cells?
86. Which has mitochondria, prokaryotic or eukaryotic cells? ______
87. What cell structure found in today’s eukaryotic cells, carry out photosynthesis? ______
88. Mitochondria and chloroplasts are the size of ______.
89. How are mitochondria and chloroplasts different than other cell organelles? ______
90. Mitochondria and chloroplasts are the same ______as prokaryotes.
91. According to the theory of endosymbiosis, mitochondria are the descendants of ______and ______eubacteria.
92. Define symbiosis. ______
93. Define aerobic. ______
94. According to the theory of endosymbiosis, where did the mitochondria in eukaryotic cells come from? ______
95. According to the theory of endosymbiosis, where did the chloroplasts in eukaryotic cells come from? ______
96. One reason it is thought that mitochondria and chloroplasts descended from bacteria is that mitochondria and chloroplasts are the same ______and ______as eubacteria.
97. Another reason it is thought that mitochondria and chloroplasts descended from bacteria is that mitochondria and chloroplasts have ______DNA similar to the chromosomes found in bacteria.
98. Another reason it is thought that mitochondria and chloroplasts descended from bacteria is that mitochondria and chloroplasts have ______similar in size and structure to that of bacteria
99. Another reason it is thought that mitochondria and chloroplasts descended from bacteria is that mitochondria and chloroplasts reproduce through simple ______like bacteria.
100. Many biologist group all living things into six broad categories called ______and the oldest of these six kingdoms are ______
101. These two kingdoms were made up of single-celled ______.
102. What was the first eukaryotic kingdom? ______
103. These organisms make up a large, varied group that includes both ______and ______organisms.
104. Three other kingdoms later evolved consisting of eukaryote. Which three are they? ______
105. The unicellular organisms today have been very successful. They make up about half of the ______on Earth.
106. Define biomass. ______
107. A unicellular organism must carry out all of the ______of the organism.
108. Different and distinct types of cells in one body can have ______functions.
109. Give an several example of specialized cells. ______
110. Almost every organism large enough to see with the naked eye is ______.
111. The development of multicellular organisms of the kingdom ______marked an important step in the evolution of life.
112. How old is the oldest know multicellular fossil? ______
113. Plantlike red, green, and brown ______are modern multicellular Protists that did not produce diverse groups of organisms.
114. Three of the multicellular groups that evolved from the protists were very successful producing three separate kingdoms. Which three kingdoms were they? ______
115. Today’s organisms probably originated during a relatively short time period between ______and ______million years.
116. The origin of today’s organisms was during the late ______and early ______periods.
117. This rapid diversification of animals is sometimes known as the “______”.
118. The ______period, which followed the Cambrian period, lasted from about 505 million to 438 million years ago.
119. During this time, many different ______continued to abound in the seas.
120. The fossil record indicates that a sudden ______occurred at the end of the Ordovician period/
121. About 440 million ears ago, a large percentage of the organism on Earth suddenly became ______.
122. ______is the death of all members of a species.
123. This was the first of ______major mass extinctions that have occurred on Earth.
124. A ______is an episode during which large numbers of species become extinct.
125. The next mass extinction of about the same size happened about ______million years ago.
126. The third mass extinction occurred at the end of the ______period about 245 million years ago.
127. About ______percent of all species of animals living at the time became extinct.
128. About ______million years later (210 million years ago), a fourth, less devastating mass extinction occurred.
129. One cause of the mass extinction could have been worldwide ______and ______changes.
130. The fifth mass extinction was ______million years ago.
131. The fifth mass extinction was the event that brought about the extinction of about two-thirds of all land species, including most of the ______.
132. Some scientists think there is a mass extinction occurring today. What do they think is causing it? ______
Name______Period___ Date______Score_____
Chapter 12 Section 3 – Life Invaded the Land
133. Early in the Earth’s history, life formed in the ______.
134. Here, life was protected from ______.
135. This made life on the land ______.
136. About 2.5 million years ago, ______by cyanobacteria began adding ______to the Earth’s atmosphere.
137. When oxygen is exposed to the sun’s rays it chemically reacts to form molecules of ______.
138. As the ozone forms in the upper atmosphere, it begins to block the ______of the sun.
139. How long did it take for enough ozone to accumulate to make the Earth’s land a safe place to live? ______
140. The first multicellular organisms to live on land many have been ______living together with plants or algae mutualistically.
141. Plants, likely evolved from photosynthetic ______.
142. During photosynthesis, plants use the ______from sunlight to make ______.
143. Why could the plants not live on bare rock? ______
144. Why can fungi not live by themselves on bare rock? ______
145. ______are symbiotic associations between fungi and the roots of plants.
146. ______is a relationship between two species in which both species benefit.
147. Plants and fungi began living together on the surface of the land about ______million years ago.
148. By 100 million years, plants had covered the surface of the Earth, forming large ______.
149. These land plants provided a ______source for land-dwelling animals.
150. What was the first animal to successfully invade the land from the sea? ______
151. Name three characteristics of arthropods. ______
152. Give four examples of arthropods. ______
153. ______were the first animals to have wings.
154. An animal with a backbone is a ______.
155. Almost all other land animals bigger than our ______are vertebrates.
156. ______first appeared in the ocean about ______million years ago.
157. Which type of fish was the most efficient predator? ______
158. For hundreds of million years, the ______is where vertebrates stayed.
159. Today, ______make up more than half of all vertebrate species.
160. Major changes had to occur in fish body organization before some descendants of fishes became capable of living on ______.
161. The first vertebrates to inhabit the land did not come out of the sea until ______million years ago.
162. What group of animals were the first land vertebrates? ______
163. Give three examples of these smooth-skinned animals. ______
164. What did amphibians develop to be able to breathe the air? ______
165. The legs of amphibians are thought to have evolved from the ______of the fish.
166. Because of their strong, flexible internal ______, the bodies of vertebrates can be much larger than those of insects.
167. ______evolved from amphibian ancestors about 340 million years ago.
168. Give four examples of modern reptiles. ______
169. The watertight reptilian skin protects against ______.
170. Reptiles also have watertight ______.
171. ______apparently evolved from feathered ______just after the Jurassic period.
172. ______were reptiles with complex teeth and legs positioned beneath their body and gave rise to ______about the same time dinosaurs evolved during the Triassic period.
173. How long ago did the fifth and last major extinction event take place on the Earth? ______
174. ______and ______eventually became the dominant vertebrates on land.
175. ______is the movement of Earth’s land masses over earth’s surface through geologic time.
176. The movement of the ______helps explain the differences on plants and animals on different areas of the world.