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# 1.2: Biology: The Study of Life

Difficulty Level: At Grade Created by: CK-12

## Lesson 1.2: True or False

Name___________________ Class______________ Date________

Write true if the statement is true or false if the statement is false.

_____ 1. A cell is the basic unit of the structure and function of all living things

_____ 2. An adaptation is a characteristic that helps a living thing survive and reproduce.

_____ 3. Natural selection is a change in the characteristics of living things over time.

_____ 4. A population consists of many different species.

_____ 5. Charles Darwin developed the theory of evolution by natural selection.

_____ 6. All living things must maintain homeostasis.

_____ 7. The characteristics of all living things are controlled by genes.

_____ 8. The four unifying principles of biology are the cell theory, the gene theory, homeostasis, and gravity.

_____ 9. Deer sometimes eat the starlings (birds) that sit on them.

_____ 10. The cells of many different organisms are very similar.

_____ 11. Simple life forms, like bacteria, have simple chemistry.

_____ 12. Simple life forms, like bacteria, do not grow and develop.

_____ 13. Every living thing begins life as a single cell.

_____ 14. The mole's touch organ is an adaptation because it helps the mole survive in its dark.

_____ 15. There are at least 100 million different species live on Earth today.

Name___________________ Class______________ Date________

Read this passage from the text and answer the questions that follow.

Evolution of Life

The diversity of life on Earth today is the result of evolution. Life began on Earth at least 4 billion years ago, and it has been evolving ever since. At first, all living things on Earth were simple, single-celled organisms. Much later, the first multicellular organisms evolved, and after that, Earth’s biodiversity greatly increased.

Today, scientists accept the evolution of life on Earth as a fact. There is too much evidence supporting evolution to doubt it. However, that wasn’t always the case.

Darwin and the Theory of Evolution

The idea of evolution has been around for centuries. In fact, it goes all the way back to the ancient Greek philosopher Aristotle. However, evolution is most often associated with Charles Darwin. Darwin published a book on evolution in 1869 titled On the Origin of Species. In the book, Darwin stated the theory of evolution by natural selection. He also presented a great deal of evidence that evolution occurs. Despite all the evidence Darwin presented, his theory was not well received at first. Many people found it hard to accept the idea that humans had evolved from an ape-like ancestor, and they saw evolution as a challenge to their religious beliefs. Darwin had actually expected this type of reaction to his theory and had waited a long time before publishing his book for this reason. It was only when another scientist, named Alfred Wallace, developed essentially the same theory of evolution that Darwin put his book into print.

Although Darwin presented a great deal of evidence for evolution in his book, he was unable to explain how evolution occurs. That’s because he knew nothing about genes. As a result, he didn’t know how characteristics are passed from parents to offspring, let alone how they could change over time.

Evolutionary Theory After Darwin

Since Darwin’s time, scientists have gathered even more evidence to support the theory of evolution. Some of the evidence comes from fossils, and some comes from studies that show how similar living things are to one another. By the 1930s, scientists had also learned about genes. As a result, they could finally explain how characteristics of organisms could pass from one generation to the next and change over time.

Using modern technology, scientists can now directly compare the genes of living species. The more genes different species share in common, the more closely related the species are presumed to be. Consider humans and chimpanzees. They share about 98% of their genes. This means that they shared a common ancestor in the not-too-distant past. This is just one of many pieces of evidence that show we are part of the evolution of life on Earth.

Questions

1. What were the first living things on Earth?

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2. Who is most often associated with developing the theory of evolution?

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3. What is the name of the process by which evolution occurs?

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4. What discovery allowed scientists to explain how characteristics are passed from parents to offspring?

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5. Cite one piece of evidence that demonstrates we are evolutionarily closely related to chimpanzees.

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## Lesson 1.2: Multiple Choice

Name___________________ Class______________ Date________

Circle the letter of the correct choice.

1. The cell theory states that
1. all living things are made up of cells.
2. living cells may come from other living cells.
3. all living things remain single-celled.
4. all of the above
2. Levels of organization of an individual organism includes
1. the tissue.
2. the population.
3. the community.
4. all of the above
3. Which is the best definition of "biology"?
1. The science of living organisms.
2. The study of humans and animals.
3. The study of plants, humans, and animals.
4. The science of life.
4. Homeostasis is
1. the ability to give rise to offspring.
2. maintaining a stable internal environment.
3. the ability to detect and respond to changes in their environment.
4. the ability to grow and develop.
5. Evolution
1. is a change in characteristics of living things over time.
2. occurs by natural selection.
3. explains how modern organisms have descended from ancient life forms.
4. all of the above
6. An example of a symbiotic relationship in which one organism is harmed is
1. the relationship between a flock of starlings and a red deer stag.
2. the relationship between a lion and an antelope.
3. the relationship between hummingbirds and flowers.
4. the relationship between humans and their pet dogs.
7. Cells
1. are all unique; no two cells are similar.
2. come from other cells, except for the very first cell of a new organism.
3. are the basic unit of structure and function of all living things.
4. are all circular in shape.
8. To be classified as a living organism, an object must
1. maintain homeostasis.
2. have a complex chemistry.
3. be made of at least one cell.
4. all of the above

## Lesson 1.2: Vocabulary I

Name___________________ Class______________ Date________

Match the vocabulary word with the proper definition.

Definitions

_____ 1. the basic unit of the structure and function of living things

_____ 2. the process by which evolution occurs

_____ 3. the same species that live in the same area

_____ 4. all of the populations that live in the same area

_____ 5. maintaining a stable internal environment

_____ 6. a change in the characteristics of living things over time

_____ 7. an individual living thing

_____ 8. the diversity of living things

_____ 9. all the living things in a given area, together with the nonliving environment

_____ 10. a characteristic that helps a living thing survive and reproduce

_____ 11. a group of similar ecosystems

_____ 12. the science of life

Terms

b. biodiversity

c. biology

d. biome

e. cell

f. community

g. ecosystem

h. evolution

i. homeostasis

j. natural selection

k. organism

l. population

## Lesson 1.2: Vocabulary II

Name___________________ Class______________ Date________

Fill in the blank with the appropriate term.

1. ____________ developed the theory of evolution by natural selection.

2. All living things grow and ____________.

3. A cell is the basic unit of the structure and ____________ of living things.

4. An adaptation is a characteristic that helps a living thing survive and ____________ in a given environment.

5. The process of maintaining a stable internal environment is ____________.

6. A ____________ is made of cells of the same kind.

7. An ____________ is an individual living thing.

8. __________ is a relationship between living things that depend on the same resources.

9. An ecosystem consists of all the living things in a given area, together with the nonliving ____________.

10. ____________ is a change in the characteristics of living things over time.

11. The ____________ is the part of Earth where all life exists.

12. ____________ is the process by which living things give rise to offspring.

## Lesson 1.2: Critical Writing

Name___________________ Class______________ Date________

Thoroughly answer the questions below. Use appropriate academic vocabulary and clear and complete sentences.

List and describe three characteristics necessary to define life.

Feb 23, 2012

Jun 08, 2015