Intro to Biology

Chapter 1

Why do Scientists Classify?

Imagine a grocery store…How are they organized?What would happen if they were not organized?

How is your life organized?

Why do Scientists Classify?

Almost 13 billion known species of organisms

Need to keep organized! (Easier to study!)

• Classification the grouping of information or objects based on similarities.

Why do Scientists Classify?

• Taxonomy is the science of grouping and naming organisms.

Useful because:once classified, scientists will know a lot about an organism

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• Broadest, most inclusive taxonBroadest, most inclusive taxon• Three domainsThree domains• ArchaeaArchaea and and EubacteriaEubacteria are are

unicellular prokaryotes (no unicellular prokaryotes (no nucleus or membrane-bound nucleus or membrane-bound organelles)organelles)

• EukaryaEukarya are more complex and are more complex and have a nucleus and membrane-have a nucleus and membrane-bound organellesbound organelles

DomainsDomains

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ArchaeaArchaea live in live in harsh environmentsharsh environments and may represent the first cells to and may represent the first cells to have evolved.have evolved.

Sewage Sewage treatment treatment

plants, plants, thermal thermal

vents, etc.vents, etc.

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EubacteriaEubacteria, some of which , some of which cause human diseases, are cause human diseases, are

present in almost present in almost all all habitatshabitats on earth. on earth.

Many bacteria are important Many bacteria are important environmentally and environmentally and

commercially.commercially.

Live in the Live in the intestines intestines of animalsof animals

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Domain Eukarya is Divided Domain Eukarya is Divided into Kingdomsinto Kingdoms

• ProtistaProtista (protozoans, algae…) (protozoans, algae…)• FungiFungi (mushrooms, yeasts …) (mushrooms, yeasts …)• PlantaePlantae (multicellular plants) (multicellular plants)• AnimaliaAnimalia (multicellular animals) (multicellular animals)

Where is life found?

• Biosphere- Earth and all of it’s living organisms

• Ecosystem- Community of living organisms in a specific area

• Population- All of the individuals of same species in the same place and time

What is alive?

• Organism- a living thing that carries out life processes

• Cells- smallest living structure that has a function

Why are all living things different?

• DNA- blueprint for an organism traits

• Gene- small part of DNA that codes for a trait

What makes up an organism?

• Bio system- combination of parts that act as a whole– Each has a unique function– Each part is controlled

• Ex. Your brain

What makes up an organism?Organism

Organ systems

Organs

Tissues

Cells

Form and Function

• How something works is related to its structure– Ex. Birds wings / fly

Fish fins / swim

Form and structure are everywhere

Reproduction/Inheritance

• When a cell divides it passes on its DNA– Copies its DNA

• Offspring gets it traits from its parent’s genes– This makes you look like your family

• DNA information (codes) comes from genes

How organisms interact with environment

• There are relationships between all living organisms

• Sun is the starting point for all food chains – Photosynthesis- chemical process where plants

take CO2 water and absorb sunlight to make food (sugar)

Energy and Life

• Producers- can make their own food

• Consumers- has to eat another organism to get energy

• Energy comes in the form of sugars and fats

Regulating our body

• Homeostasis- how our body maintains “stable” internal conditions

– Ex. Blood pressure, heart rate, body temperate

Why do species change?

• Adaptation- change to survive their environment

• Survival of the fittest– Natural selection

• Those who can survive will

What does change lead to?

• Evolution- adaptations (changes) from generation to generation can lead to a new species

Inheritance

• When a cell divides it passes on it’s DNA– Copies it’s DNA

• Offspring get their traits from their parent’s genes– Makes you look like your family

• DNA information (code) comes from genes