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The Living World

Chapter 1: The Science of Biology

Specific Learning Outcomes:

1.1 List the major properties of life.

1.2 Explain how science is distinguished from other

ways of seeking understanding of life.

1.3 Explain the significance of major unifying themes of

modern biology.

1.4 Explain the limitations of science.

1.5 Identify how the steps in the scientific process were

used to determine the effects of CFCs on the earth’s

ozone layer.

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1.1 The Diversity of Life

Biology is the study of living things

Living things can be divided into

six kingdoms

Fig. 1.1

Archaea

Bacteria

Protista

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1.2 Properties of Life

Biology is the study of life

But what does it mean to be alive?

Living organisms and many non-living things

share three properties

Complexity

Movement

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1.2 Properties of Life

All living organisms share five basic properties

1. Cellular Organization

All living organisms are composed of at least one cell

2. Metabolism

All living organisms use energy

3. Homeostasis

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1.2 Properties of Life

All living organisms share five basic properties

4. Growth and reproduction

All living organisms grow and reproduce

5. Heredity

All living organisms possess a genetic system that is

based on DNA

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1.4 Biological Themes

The living world is

organized by major

themes

Indeed, five general

themes unify and explain

biology as a science

Refer to Table 1.1

Evolution, cooperation, flow of energy

structure determines function, and

homeostasis

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1.4 Biological Themes

1. Evolution

The genetic change in a species over time

It is a result of a process termed

natural selection

Variation may also be caused by

artificial selection

2. The Flow of Energy

All living organisms require energy

The sun is the source of energy for ecosystems

Plants capture energy via photosynthesis

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1.4 Biological Themes

3. Cooperation

Cooperation between organisms is critical for

evolution

Symbiosis

occurs when two organisms of different

species live in direct contact

4. Structure Determines Function

Biological structures are well suited to their

function

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1.4 Biological Themes

5. Homeostasis

All living organisms act to maintain a relatively

stable internal environment

Maintaining homeostasis requires a lot of

signaling back-and-forth between cells

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1.5 How Scientists Think

Deductive Reasoning

Using accepted general principles as a “guide” to

explain specific observations

It is the reasoning of

Mathematics

Philosophy

Politics

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1.5 How Scientists Think

Inductive Reasoning

Discovering general principles through

examination of specific cases

It is used by scientists to develop

hypotheses

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1.6 Science in Action: A Case Study

In 1985, a scientist discovered low levels of

ozone in the upper Antarctic atmosphere

The culprit was later revealed to be

chlorofluorocarbons (CFCs)

Coolants in air conditions; propellants in aerosols

CFCs condense into tiny ice crystals

Warmed by the sun, they attack and

destroy ozone

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1.6 Science in Action: A Case Study

The ozone layer protects us from the sun’s

ultraviolet (UV) rays

1% drop in ozone Æ 6% increase in skin cancers

Its depletion is a serious world problem

So governments have rushed to correct the

situation

There is now a worldwide reduction in CFC

production

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1.7 Stages of a Scientific Investigation

The

scientific process

can be divided into six

stages

1. Observation

Careful observation of a process or phenomenon

Question asked

2. Hypothesis

A probable answer regarding the observation

If more than one answer,

alternative hypotheses

are

formed

3. Prediction

Expected consequences based on the correct

hypothesis

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1.7 Stages of a Scientific Investigation

The

scientific process

can be divided into six

stages

4. Testing

The hypothesis is tested through an

experiment

5. Controls

A factor that influences a process is called a

variable

In a

control experiment

, all variables are held constant

6. Conclusion

Based on the results of the experiment, a hypothesis

is either accepted or rejected

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Hypothesis

Observation

Experiment

Conclusion

Prediction

Question

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Observation

Fig. 1.7

Question

Hypothesis 1

Hypothesis 2

Hypothesis 3

Hypothesis 4

Hypothesis 5

Potential

hypotheses

Experiment

Reject

hypotheses

1 and 4

Hypothesis 5

Hypothesis 3

Hypothesis 2

Remaining

possible

hypotheses

Experiment

Reject

hypotheses

2 and 3

Last remaining

possible hypothesis

Hypothesis 5

Predictions

Experiment 1

Experiment 2

Experiment 3

Experiment 4

Predictions

confirmed

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1.8 Theory and Certainty

A

theory

is a set of hypotheses that have been

tested many times and not rejected

It indicates a higher degree of certainty

However, there is no absolute truth in science

So the acceptance of a theory is provisional

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1.8 Theory and Certainty

Note:

To scientists, a theory represents that of

which they are most certain

To the general public, a theory represents

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1.8 Theory and Certainty

The limitations of science

It is limited to organisms and processes that

can be observed and measured

Supernatural and religious phenomena are

beyond the scope of science

There are also practical limits

Science cannot be relied upon to solve all

problems

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The Living World

Chapter 1: The Science of Biology

Specific Learning Outcomes:

1.1 List the major properties of life.

1.2 Explain how science is distinguished from other

ways of seeking understanding of life.

1.3 Explain the significance of major unifying themes of

modern biology.

1.4 Explain the limitations of science.

1.5 Identify how the steps in the scientific process were

used to determine the effects of CFCs on the earth’s

ozone layer.

Figure

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