Study of Biology 1

What is Biology? Biology is the study of all living things Living things are called organisms Organisms include bacteria, protists, fungi, plants, & animals 2

All Living Things Share Common Characteristics 1.Basic Unit is the Cell 2.They Reproduce 3.All Based On Universal Genetic Code (DNA) 4.Grow & Develop 3

Common Characteristics 5.Obtain & Use Materials & Energy 6.Respond To Their Environment 7.Maintain A Stable Internal Environment 8.AS A GROUP, Living Things Evolve, That Is They Change Over Time 4

Characteristics of Organisms 5

All Organisms are made of Cells 6

Facts About Cells Cells are the smallest living unit of an organism All cells contain living material called cytoplasm All cells are surrounded by a cell membrane that controls what enters & leaves the cell 7

More Cell Facts Cells are complex & highly organized Cells have parts called organelles that do different jobs e.g. Chloroplasts in plants make sugars 8

Organisms are Grouped by their Number of Cells Unicellular Organisms – Living Organism Made Up Of One Cell Multicellular Organisms – Living Organism Made Up Of Many, Specialized Cells 9

Organisms Reproduce to Pass on their Genetic Traits 10

Two Types of Reproduction Sexual Reproduction Involves 2 parents Egg fertilized by sperm to make a ZYGOTE Offspring DIFFERENT from parents 11

Two Types of Reproduction Asexual Reproduction Involves a single organism or cell Cell divides Offspring IDENTICAL to parent 12

Cells Have a Genetic Code 13

Genetic Code DNA (deoxyribose nucleic acid) carries the genetic code for all organisms All organisms contain DNA DNA codes for the proteins that make up cells & do all the work 14

Organisms Grow & Develop 15

Growth & Development Organisms grow by producing MORE CELLS & by cell ENLARGEMENT Organisms develop as they mature into an adult organism 16

Cells Require Food & Energy 17

Food Requirements Autotrophs can make their own food Photoautotrophs use sunlight to make food (photosynthesis) Chemoautotrophs use chemicals such as iron & sulfur as their energy 18

Food Requirements Heterotrophs can NOT make their own food They must consume other organisms Herbivores eat plants Carnivores eat meat Omnivores eat plants & animals 19

Metabolism Sum of all the chemical reactions in an organism All require energy Sunlight is the ultimate energy for life on Earth copyright cmassengale20

Metabolism Cellular Respiration – Cells releasing the chemical energy stored in foods 6O 2 + C 6 H 12 O 6 6CO 2 + 6H 2 O copyright cmassengale21

Organisms Respond to Stimuli Organisms Respond to stimuli (Temperature, Water, Food Supplies, etc.) In Order To Survive & Reproduce copyright cmassengale22

Homeostasis Keeping The Internal Environment (Homeostasis) Of The Cell or Organism Within The Ranges Required For Life Stable internal conditions of pH, temperature, water balance, etc. 23

Living Things Evolve Groups Of Organisms (Not Individuals) Change Over Time In Order To Survive Within Changing Environments. Fossil records show changes in groups of organisms 24

Life is Organized on Several Levels 25

Levels Atoms Molecules Organelles Cells – life starts here Tissues Organs System Organism 26

Levels Population Community Ecosystem Biosphere 27

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