Study of Biology copyright cmassengale1. What is Biology? Biology is the study of all living things Living things are called organisms Organisms include

Study of Biology

copyright cmassengale 1

What is Biology?

• Biology is the study of all living things

• Living things are called organisms

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


All Living Things Share Common Characteristics

1. Basic Unit is the Cell2. They Reproduce3. All Based On Universal

Genetic Code (DNA)4. Grow & Develop


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


Characteristics of Organisms


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All Organisms are made of Cells


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


More Cell Facts• Cells are complex &

highly organized• Cells have parts

called organelles that do different jobs

e.g. Chloroplasts in plants make sugars


More Cell Facts• The simplest cells

are called Prokaryotes

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

• Bacteria are examples copyright cmassengale 9

More Cell Facts• More complex cells

are called Eukaryotes

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

• Plants, animals, protists, & fungi are examples


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


Organisms Reproduce to Pass on their Genetic

Traits


Two Types of Reproduction

• Sexual Reproduction

• Involves 2 parents

• Egg fertilized by sperm to make a ZYGOTE

• Offspring DIFFERENT from parents


Two Types of Reproduction

• Asexual Reproduction

• Involves a single organism or cell

• Cell divides• Offspring

IDENTICAL to parent


Cells Have a Genetic Code


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


Organisms Grow & Develop


Growth & Development

• Organisms grow by producing MORE CELLS & by cell ENLARGEMENT

• Organisms develop as they mature into an adult organism


Cells Require Food & Energy


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


Food Requirements

• Heterotrophs can NOT make their own food

• They must consume other organisms

• Herbivores eat plants• Carnivores eat meat• Omnivores eat plants & animals


Metabolism

• Sum of all the chemical reactions in an organism

• All require energy• Sunlight is the ultimate

energy for life on Earth


Metabolism

• Cellular Respiration –Cells releasing the chemical energy stored in foods

6O2 + C6H12O6 6CO2 + 6H2O


Organisms Respond to Stimuli

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


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.


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 organismscopyright cmassengale 26

Life is Organized on Several Levels


Levels• Atoms• Molecules• Organelles• Cells – life starts

here• Tissues• Organs• System• Organism


Levels

• Population• Community• Ecosystem• Biosphere




Documents

Study of Biology copyright cmassengale1. What is Biology? Biology is the study of all living things Living things are called organisms Organisms include