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Chapter 1 The Study of Chapter 1 The Study of LifeLife

1.1 Introduction to Biology1.1 Introduction to Biology

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Biology is the study of lifeBiology is the study of life

There are many There are many different types of different types of living things; living things; many (or most) many (or most) haven’t been haven’t been discovered yet.discovered yet.

Snowy the albino echidna

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Biology is the study of lifeBiology is the study of life In Biology you will study In Biology you will study

the features of living the features of living things and how they work.things and how they work.

the interactions of living the interactions of living things with each other and things with each other and the nonliving world.the nonliving world.

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What Biologists DoWhat Biologists Do Study the diversity of Study the diversity of

lifelife Research diseasesResearch diseases Develop technologiesDevelop technologies Improve agricultureImprove agriculture Preserve the Preserve the

environmentenvironment

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Characteristics of Living ThingsCharacteristics of Living Things

Alive or not?Alive or not?

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Characteristics of Living ThingsCharacteristics of Living Things Living things are Living things are

made of cells.made of cells.The cell is the basic The cell is the basic unit of life.unit of life.All living things are All living things are composed of one or composed of one or more cells containing more cells containing DNA (the hereditary DNA (the hereditary material) that function material) that function in an organized way.in an organized way.

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Characteristics of Living ThingsCharacteristics of Living Things Living things display Living things display

organization.organization. Atoms form molecules, groups of Atoms form molecules, groups of

molecules form cells, cells form molecules form cells, cells form tissues, different tissues working tissues, different tissues working together form organs, organs together form organs, organs working together form organ working together form organ systems and organ systems systems and organ systems working together to support an working together to support an organism.organism.

Structure fits function is a major Structure fits function is a major theme in biology.theme in biology.

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Characteristics of Living ThingsCharacteristics of Living Things

Living things grow and Living things grow and develop.develop.

Growth is the addition Growth is the addition of mass while of mass while development is the development is the process of changes that process of changes that occur throughout the occur throughout the life of an organism.life of an organism.

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Characteristics of Living ThingsCharacteristics of Living Things

Living things reproduce.Living things reproduce.Organisms reproduce Organisms reproduce and pass along traits and pass along traits from one generation to from one generation to the next. For a species the next. For a species to continue to exist, to continue to exist, reproduction must reproduction must occur.occur.Reproduction can be Reproduction can be asexual or sexual.asexual or sexual.

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Characteristics of Living ThingsCharacteristics of Living Things Living things respond to Living things respond to

stimuli.stimuli.

All organisms live in All organisms live in constant interface with constant interface with environment: air, water, environment: air, water, weather, temperature, weather, temperature, other organisms…other organisms…

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Characteristics of Living ThingsCharacteristics of Living Things

Stimulus: Stimulus: condition in condition in the environment that the environment that causes an organism to causes an organism to adjustadjust

Response: Response: reaction to a reaction to a stimulusstimulus

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Characteristics of Living ThingsCharacteristics of Living Things Living things maintain Living things maintain

homeostasis.homeostasis. Many responses Many responses

organisms make are organisms make are internal regulations internal regulations make to maintain a make to maintain a “steady state”“steady state”

Homeostasis: Homeostasis: maintaining steady maintaining steady state, takes energy.state, takes energy.

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Characteristics of Living ThingsCharacteristics of Living Things Living things require energy.Living things require energy.

Energy is the ability to do Energy is the ability to do work and is required for all work and is required for all life processes.life processes.

Organisms get energy from Organisms get energy from food.food.

Plants, some Protists, and Plants, some Protists, and some bacteria make their some bacteria make their own food in the process of own food in the process of photosynthesis (producers).photosynthesis (producers).

Animals, fungi, some Animals, fungi, some Protists and some bacteria Protists and some bacteria need to consume food need to consume food (consumers).(consumers).

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Characteristics of Living ThingsCharacteristics of Living Things In living things In living things

adaptations evolve over adaptations evolve over time.time.

Adaptation are inherited Adaptation are inherited changes that occur over changes that occur over time to enable an time to enable an organism to respond to organism to respond to stimuli and better stimuli and better survive IN AN survive IN AN ENVIRONMENT.ENVIRONMENT.

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Characteristics of Living ThingsCharacteristics of Living Things Gradual accumulation Gradual accumulation

of adaptations over time of adaptations over time is EVOLUTIONis EVOLUTIONFourth marking period Fourth marking period we study evolution and we study evolution and find that some find that some organisms evolve organisms evolve slowly (horse) while slowly (horse) while others evolve within our others evolve within our lifetime (bacteria).lifetime (bacteria).

A Systematic Approach

The scientific method is a systematic approach used in scientific study, whether it is chemistry, physics, biology, or another science.

It is an organized process used by scientists to do research, and provides methods for scientists to verify the work of others.

A Systematic Approach (cont.)

The steps in a scientific method are repeated until a hypothesis is supported or discarded.

An observation is the act of gathering information.

– Qualitative data is obtained through observations that describe color, smell, shape, or some other physical characteristic that is related to the five senses.

– Quantitative data is obtained from numerical observations that describe how much, how little, how big or how fast.

A Systematic Approach (cont.)

A hypothesis is a tentative explanation for what has been observed.

An experiment is a set of controlled observations that test the hypothesis.

A Systematic Approach (cont.)

A variable is a quantity or condition that can have more than one value.

– An independent variable is the variable you plan to change.

– The dependent variable is the variable that changes in value in response to a change in the independent variable.

A Systematic Approach (cont.)

A control is a standard for comparison in the experiment.

A conclusion is a judgment based on the information obtained from the experiment.

– A hypothesis is never proven, only supported or discarded.

– A model can be used to make predictions.

A Systematic Approach (cont.)

A theory is an explanation that has been repeatedly supported by many experiments.– A theory states a broad

principle of nature that has been supported over time by repeated testing.

– Theories are successful if they can be used to make predictions that are true.

Theory and Scientific Law

Section 1-3Section 1-3A scientific law is a

relationship in nature that is supported by many experiments, and no exceptions to these relationships are found.

Theory and Scientific Law (cont.)