Worksheet 12.3-12.6 Chapter 12.4: Early Single

Worksheet
12.3-12.6
Chapter 12.4: Early Single-Cell Organisms
Single-celled organisms existed 3.8 billion years ago. Microbes have changed the physical and chemical composition of
Earth.
1. What are two ways that early single-celled organisms changed Earth’s surface?
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2. What have scientists inferred from fossil stromatolites?
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Fill in the blanks with the correct terms.
3. Although prokaryotes existed as long as 3.5 billion years ago, __________
arose about 1.5 billion years ago.
4. Eukaryotes have a __________ and membrane-bound organelles.
5. Eukaryotes are _____________, which means they need oxygen to survive.
6. While the first eukaryotes were made of only one __________, later eukaryotes were made of many
7. Look at page 373 in the textbook, and use the sequence diagram below to summarize the theory of endosymbiosis
8. What important events occurred during the Paleozoic era?
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9. What were some of the key appearances and radiations in the Mesozoic era?
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Describe the role that cyanobacteria play in Earth’s early development
13. What is the main advantage of asexual reproduction?
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14. Sexual reproduction increases genetic variation in a population. Why might this be beneficial to the population?
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15. Bacteria that can carry out photosynthesis are called ________________
.
16. How do you think the evolution of flowering plants affected the evolution and radiation of birds?
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17. The mutually beneficial relationship in which one organism lives within the body of another is called
.
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Chapter 12.5: Radiation of Multicellular Life
1. How does a great diversity of organisms increase the chances that some will survive a major change in the
environment?
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2. How do you think the evolution of flowering plants affected the evolution and radiation of birds?
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Multicellular life evolved in distinct phases. Fill in the graphic organizer below for each of the eras shown.
Vocabulary Check
Paleozoic
Cambrian Explosion
Mesozoic
Cenozoic
10.
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Divided into the Triassic, Jurassic, and Cretaceous periods
11.
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Ended with a mass extinction with more than 90 percent of all marine life extinct
12.
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Earliest part of Paleozoic era
13.
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Primates evolved during this era
14.
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Trilobites were abundant then
15.
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Rise of the first marsupial mammals
16.
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Divided into Tertiary and Quaternary periods
17.
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Life moved onto land
18.
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Includes the Carboniferous period
19.
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Dinosaurs roamed the earth
20.
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Continues today
Chapter 12.6: Primate Evolution
Humans appeared late in Earth’s history. Use Figure 12.18 in the textbook to help you fill in the concept map below with
the correct primate group
10. What are the two groups that most hominid species are classified into?
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11. What early hominid was known as “handy man”?
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12. What early hominid group may have existed alongside modern humans?
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13. Modern humans arose about 200,000 years ago. What trends can be seen in tools from older to more recent fossil
sites of Homo?
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14. What evidence supports the hypothesis that primate brains evolved faster than rodent brains in the past?
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Vocabulary Check
Primate
Prosimians
Anthropoid
Hominids
15.
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Walks upright, has long lower limbs, opposable thumbs, and large brains
16.
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Oldest living primate group
17.
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Name means humanlike primate
18.
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Has flexible hands and feet, eyes that face forward, and large brains
19.
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Small primate that is active at night
20.
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Includes all species in human lineage, both modern and extinct
21.
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Examples include lemurs, lorises, and tarsiers
22.
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Divided into New World monkeys, Old World monkeys, and hominoids