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Study of BiologyStudy of Biology

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What is Biology?What is Biology?BiologyBiology is the study of all living is the study of all living thingsthings

Living things are called Living things are called organismsorganisms

All organisms share All organisms share seven seven characteristics of lifecharacteristics of life

1. All organisms are made 1. All organisms are made

of of CELLSCELLSCells are the Cells are the smallest living unitsmallest living unit of an organismof an organism

Organisms are grouped by their Organisms are grouped by their number of cellsnumber of cells– Unicellular Organisms: Unicellular Organisms: made up of made up of

one cellone cell– Multicellular Organisms:Multicellular Organisms:made up of made up of

many cellsmany cells

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2. All organisms 2. All organisms REPRODUCEREPRODUCE to pass on to pass on their genetic traitstheir genetic traits

Two Types of Reproduction:Two Types of Reproduction:

A: Sexual Reproduction: A: Sexual Reproduction: involves involves two organisms; an egg is fertilized by two organisms; an egg is fertilized by sperm; offspring DIFFERENT from sperm; offspring DIFFERENT from parentsparents

B: B: Asexual Reproduction: Asexual Reproduction: involves involves a single organism (cell); cell divides in a single organism (cell); cell divides in half; offspring IDENTICAL to parenthalf; offspring IDENTICAL to parent

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3. All organisms have a 3. All organisms have a genetic code called genetic code called DNADNA

DNADNA (deoxyribonucleic acid) (deoxyribonucleic acid) carries the genetic code for all carries the genetic code for all organismsorganisms

DNA DNA codes for the proteinscodes for the proteins that that make up cells & make up cells &

perform cell functionsperform cell functions

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4. All organisms 4. All organisms GROW & GROW & DEVELOPDEVELOP

Organisms Organisms growgrow by producing by producing more cells & by more cells & by cell enlargementcell enlargement

Organisms Organisms developdevelop as they as they mature into an mature into an adult adult

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5. All organisms require 5. All organisms require ENERGYENERGY

The ultimate source of ALL energy is The ultimate source of ALL energy is the sun.the sun.

Organisms gain energy in the form of Organisms gain energy in the form of food.food.– AutotrophsAutotrophs: make their own food : make their own food

(energy) using the sun or chemicals(energy) using the sun or chemicals– HeterotrophsHeterotrophs: consume other organisms : consume other organisms

for food (energy)for food (energy)

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6. All Organisms 6. All Organisms RESPOND TO THEIR RESPOND TO THEIR ENVIRONMENT ENVIRONMENT

Organisms respond to both their external and internal environment

Organisms respond to temperature, water, food supplies, light, etc. in order to survive and reproduce 88

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**HOMEOSTASIS***HOMEOSTASIS***The process of maintaining the internal

environment of an organism. (Stability)If not maintained, the organism will die. Stable internal conditions of pH, temperature, water, salt, blood sugar, etc. must be maintained.

7. All Organisms EVOLVE

Groups Of Organisms, (not individuals) change over time in order to adapt and survive within changing environments.

Fossil records show changes in groups of organisms

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Organisms are grouped into Organisms are grouped into Six KingdomsSix Kingdoms

1. 1. BacteriaBacteria: E. coli, streptococcus, : E. coli, streptococcus, stapholococcusstapholococcus

2. 2. ArchaeaArchaea: methanogens, halophiles, : methanogens, halophiles, thermophilesthermophiles

3. 3. ProtistsProtists: seaweed, algae, amoeba: seaweed, algae, amoeba

4. 4. FungiFungi: mushrooms, yeast, mold: mushrooms, yeast, mold

5. 5. PlantsPlants: moss, grass, flowers: moss, grass, flowers

6. 6. AnimalsAnimals: sponge, grasshopper, lion: sponge, grasshopper, lion

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What about What about Viruses?Viruses?

Viruses are Viruses are NOTNOT considered living considered living organisms.organisms.

They They require a host cell require a host cell in order to in order to survive and reproduce.survive and reproduce.– While they do have some of the While they do have some of the

characteristics of life, they obtain them characteristics of life, they obtain them from their host.from their host.

– Without a host, the virus will die.Without a host, the virus will die.

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