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Chapter 1A

•It’s ALIVE

or is it

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Section 1• Characteristics of living things:• There are 6 that all organisms share

• Living things have cells

• Living things sense and respond to change

• Living things reproduce

• Living things have DNA

• Living things use energy

• Living things grow and develop

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Living things have cells…..

• All living things are made of cells

• Cell – a membrane bound structure that contains all the necessary things for life

• Some organisms are made of only one cell – UNICELLULAR

• Some organisms are made of more than one cell - MULTICELLULAR

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Unicellular…..

Amoeba

Euglena

Paramecium

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Multicellular…..

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Living things sense and respond to change…

• Organisms respond to a STIMULUS

– STIMULUS …….anything that causes a change in the organisms activities

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Why?????

• To maintain HOMEOSTASIS

–Maintaining a stable internal environment

• Keeping your body temp. @ 98.6

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Living Things Reproduce…..

• 2 Types of Reproduction:

– Asexual

– Sexual

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Asexual Reproduction

• Only involves one parent

• Offspring look identical to parent

• Examples:

- Starfish

– Strawberry

– Bacteria

– Amoeba

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Sexual Reproduction

• Involves 2 parents

• Offspring look similar to both parents

• Examples:

• Human

• Fish

• Dogs

• Cats

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Living Things Have DNA…..

• DNA – Deoxyribonucleic Acid

• - used by cells to make protein

• - passed on to new cells during reproduction

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Living Things Use Energy…..

• Organisms need energy to carry out these processes

• The rate at which your body uses energy is your METABOLISM

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Living Things Grow and Develop…..

• All organisms grow and go through changes during periods of their lives

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Section 2

• The simple bare necessities of life:

»Food

»Water

»Air

»Space

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Food

• All organisms need food…..WHY ?

• Producers – makes food

• Example – plant

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• Consumers – eat food

• Example - cow

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• Decomposer – breaks down dead organisms for their food

• Example: termites

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Water

• Most cells are made of water…how much?– About 70%

– Why so much ?

» To help run all the processes necessary to keep the cell alive

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Air

• Mixture of several gases

• Two of the most commonly used gases:

• Oxygen

• Carbon Dioxide

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Space

• An organism will try to keep it’s niche the same

– Niche…..the environment where the organism lives with the effect of all living and non-living factors in that

environment

– Some organisms need more area than others

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Section 3

• The Chemistry of life:

– Everything is made of atoms

– Approx. 100 kinds of atoms

– Atoms are the smallest particles to make up things

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Atoms make up…..

• Molecules – 2 or more atoms joined together

• Found in living things are made up of different combinations of 6 elements:

• C – Carbon

• H – Hydrogen

• O – Oxygen

• N – Nitrogen

• P – Phosphorus

• S – Sulfur

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Atoms also make up…..• Elements – made of

all one atoms

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Proteins…..

• Second most abundant in cells

• Made of Amino Acids

• We eat foods high in protein, our body breaks the protein into amino acids, then they are reassembled inside the cells of our body

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Proteins…..

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Proteins…..

• Found in what foods ?

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Carbohydrates…..

• Made of sugars

• Used as an energy source

• 2 types of Carbohydrates

• Simple

• Complex

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Carbohydrates…..

• Simple – made of one sugar molecule or a few sugar molecules linked together

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Carbohydrates…..

• Complex – made of hundreds of sugar molecules linked together

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Lipids…..

• Compounds that can not mix with water

• Some store energy

• Some form the membrane of cells

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Lipids…..

• Fats and Oils – Store energy

• - get burned after carbohydrates

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Lipids…..

• Phospholipids – form the cell membrane

• - heads like water

• - tails do not like water

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Nucleic Acids…..

• Made up of Nucleotides

• A Nucleotide is made of » Sugar

» Phosphate

» Base

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Nucleotides…..

• DNA is made of Nucleotides

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The Cell’s Fuels…..

• ATP – Adenosinetriphosphate is the major fuel used by cells.