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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 is the study of all living thingsliving things

• Living things are called Living things are called organismsorganisms

• Organisms include bacteria, Organisms include bacteria, protists, fungi, plants, & protists, fungi, plants, & animalsanimals

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All Living Things Share All Living Things Share Common Common

CharacteristicsCharacteristics1.1. Basic Unit is the Basic Unit is the CELL, CELL,

COMPOSED OF ONE OR COMPOSED OF ONE OR MORE CELLS.MORE CELLS.

2.2. They They Reproduce-Reproduce-All Based All Based On Universal Genetic On Universal Genetic Code Code (DNA)(DNA)

3.3. Grow & DevelopGrow & Develop

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Common Common CharacteristicsCharacteristics

4. 4. RespondRespond To Their To Their Environment- Maintain Environment- Maintain A A Stable Internal Stable Internal EnvironmentEnvironment5. Requiring,Obtaining & Using 5. Requiring,Obtaining & Using Materials & Materials & EnergyEnergy

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I. Characteristics of I. Characteristics of OrganismsOrganisms

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1. 1. Basic Unit is the Basic Unit is the CELL, CELL, COMPOSED OF ONE OR COMPOSED OF ONE OR

MORE CELLSMORE CELLS..

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Facts About CellsFacts About Cells• Cells are the Cells are the smallest living smallest living

unitunit of an organism of an organism• All cells contain living All cells contain living

material called material called cytoplasmcytoplasm• All cells are surrounded by a All cells are surrounded by a

cell membranecell membrane that controls that controls what enters & leaves the cellwhat enters & leaves the cell

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More Cell FactsMore Cell Facts• Cells are complex & Cells are complex &

highly highly organizedorganized• Cells have parts Cells have parts

called called organellesorganelles that that do different jobsdo different jobs

e.g. Chloroplasts in e.g. Chloroplasts in plants make sugarsplants make sugars

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More Cell FactsMore Cell Facts• The simplest cells The simplest cells

are called are called ProkaryotesProkaryotes

• These cells These cells DO NOT DO NOT have a nucleus or have a nucleus or membrane-bound membrane-bound organellesorganelles

• BacteriaBacteria are are examplesexamples

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More Cell FactsMore Cell Facts• More complex cells More complex cells

are called are called EukaryotesEukaryotes

• These cells These cells DO have DO have a nucleus and a nucleus and membrane-bound membrane-bound organellesorganelles

• Plants, animals, Plants, animals, protists, & fungiprotists, & fungi are are examplesexamples

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Organisms are Grouped by Organisms are Grouped by their Number of Cellstheir Number of Cells

• Unicellular OrganismsUnicellular Organisms– Living Organism Made Up Of Living Organism Made Up Of

One CellOne Cell

• Multicellular OrganismsMulticellular Organisms– Living Organism Made Up Of Living Organism Made Up Of

Many, Specialized CellsMany, Specialized Cells

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2. 2. They They Reproduce-Reproduce-passing on passing on their traits Based On their traits Based On

Universal Genetic Universal Genetic Code Code (DNA)(DNA)

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Two Types of Two Types of ReproductionReproduction

Sexual ReproductionSexual ReproductionInvolves a TWO PARENTS Involves a TWO PARENTS PRODUCING A SINGLE or MULTIPLE PRODUCING A SINGLE or MULTIPLE OFFSPRINGOFFSPRING

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Two Types of Two Types of ReproductionReproduction

• Asexual Asexual ReproductionReproduction

• Involves a single Involves a single organism or cellorganism or cell

• Cell dividesCell divides• Offspring Offspring

IDENTICAL to IDENTICAL to parentparent

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Cells Have a Genetic Cells Have a Genetic CodeCode

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Genetic CodeGenetic Code

• DNADNA ( (deoxyribose nucleic deoxyribose nucleic acidacid) carries the genetic code ) carries the genetic code for all organismsfor all organisms

• All organismsAll organisms contain DNA contain DNA• DNA DNA codes for the proteinscodes for the proteins

that make up cells & do all that make up cells & do all the workthe work

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3. Organisms Respond to 3. Organisms Respond to StimuliStimuli

• Organisms Organisms RespondRespond to to stimulistimuli (Temperature, Water, (Temperature, Water, Food Supplies, etc.) Food Supplies, etc.) In Order In Order To Survive & ReproduceTo Survive & Reproduce

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HomeostasisHomeostasis

• Keeping The Internal Keeping The Internal Environment Environment (Homeostasis)(Homeostasis) Of Of The Cell or Organism Within The The Cell or Organism Within The Ranges Required For LifeRanges Required For Life

• Stable internal conditions of Stable internal conditions of pH, pH, temperature, water balance, etctemperature, water balance, etc..

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4. Organisms Grow & 4. Organisms Grow & DevelopDevelop

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Growth & DevelopmentGrowth & Development

• Organisms Organisms growgrow by by producing MORE producing MORE CELLS & by cell CELLS & by cell ENLARGEMENTENLARGEMENT

• Organisms Organisms developdevelop as they mature into as they mature into an adult organisman adult organism

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5. Require,Obtain & Use 5. Require,Obtain & Use Materials & Materials & EnergyEnergy

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Food RequirementsFood Requirements• Autotrophs can Autotrophs can

make their own foodmake their own food• Photoautotrophs use Photoautotrophs use

sunlight to make sunlight to make food food (photosynthesis)(photosynthesis)

• Chemoautotrophs Chemoautotrophs use chemicals such use chemicals such as iron & sulfur as as iron & sulfur as their energytheir energy

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Food RequirementsFood Requirements

• HeterotrophsHeterotrophs can NOT make can NOT make their own foodtheir own food

• They must consume other They must consume other organismsorganisms

• HerbivoresHerbivores eat plants eat plants• CarnivoresCarnivores eat meat eat meat• OmnivoresOmnivores eat plants & animals eat plants & animals

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MetabolismMetabolism

• Sum of all the chemical Sum of all the chemical reactions in an organismreactions in an organism

• All All require energyrequire energy• SunlightSunlight is the ultimate is the ultimate

energy for life on Earth energy for life on Earth

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MetabolismMetabolism

•Cellular RespirationCellular Respiration – Cells releasing the chemical Cells releasing the chemical

energy stored in foodsenergy stored in foods

6O6O22 + C + C66HH1212OO66 6CO 6CO22 + + 6H6H22OO

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Life is Organized on Life is Organized on Several LevelsSeveral Levels

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What are the levels of organization of living things?

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Levels of Levels of Organization of Organization of Living ThingsLiving Things• AtomsAtoms

• MoleculesMolecules• OrganellesOrganelles• CellsCells – life starts – life starts

herehere• TissuesTissues• OrgansOrgans• SystemSystem• OrganismOrganism

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Levels cont…Levels cont…

• PopulationPopulation• CommunityCommunity• EcosystemEcosystem• BiosphereBiosphere

Atoms

A unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons.

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Branches of Biology

Molecules

Groups of atoms; smallest unit of most chemical compounds

Water DNA

Organelles

• Specialized structure found in a cell that has a specific function

• Ex. mitochonria

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Branches of Biology

Cells

Smallest functional unit of life

Nerve cell

Tissue

• Group of cells organized together that are performing together for a specific function.

• Ex. nerve tissue

Organs

• Groups of tissues that are working together for a specific function

• Ex. brain

Organ System

• Group of organs that are working together to make one of the body systems.

• Ex. Nervous system

Branches of Biology

Organism

Individual living thing

Bison

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Branches of Biology

Population

Group of organisms of one type that live in the same area

Bison herd

Branches of Biology

Community

Populations that live together in a defined area

Hawk, snake, bison, prairie dog, grass

Branches of Biology

Ecosystem

Community and its nonliving surroundings

Hawk, snake, bison, prairie dog, grass, stream, rocks, air

BIOME• Some parts of the earth have more

or less the same kind of abiotic and biotic factors spread over a large area creating a typical ecosystem over that area. Such major ecosystems are termed as biomes.

Biosphere

The part of Earth that contains all ecosystems. From the broadest biophysiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydrosphere and atmosphere.

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