Characteristics of Life8 Life Functions

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 a

group of characteristics.

8 Life Processes

• Something is only alive if it does all eight processes.

1. Transport2. Regulation3. Nutrition4. Grow & Develop5. Excretion6. Respiration7. Synthesis8. Reproduction

Transport• All living things circulate materials• Individual cells must circulate

materials within themselves• Organisms must be able to transport

materials around the entire organism• Nutrients and wastes are two

materials that are transported.

Regulation• All living things are sensitive• They respond to their environment• All living things respond to changes in their

environment. Living things notice changes in their surroundings and react to them. They maintain an internal balance called homeostasis.

• Eg. Plants grow towards the light.

• Eg. People react to the temperature around them

Regulation• Organisms Respond to stimuli

(Temperature, Water, Food Supplies, etc.) In Order To Survive & Reproduce

Nutrition• Food is used to provide energy.• Green plants make their own food using

sunlight.• Animals eat plants or other animals.• Autotrophs can make their own food• Photoautotrophs use sunlight to make

food (photosynthesis)• Chemoautotrophs use chemicals such as

iron & sulfur as their energy

Growth and Development

• Organisms grow by producing MORE CELLS & by cell ENLARGEMENT

• Organisms develop as they mature into an adult organism

Excretion• All living things get rid of wastes• Waste substances must be removed

from the body.

• Plants and animals both need to get rid of waste gas and water.

Respiration• Plants and animals use the oxygen in the air to turn

food into energy.• This process occurs on a cellular level• All living things require Food & Energy• Cellular Respiration –Cells releasing the chemical energy stored

in foods

6O2 + C6H12O6 6CO2 + 6H2O

Synthesis• All living organisms create complex

substances in their bodies from simpler ones.

DNA (deoxyribose nucleic acid) carries the genetic code for all organismsAll organisms contain DNADNA codes for the proteins that make up cells & do all the work

Reproduction• Organisms Reproduce to Pass on their

Genetic Traits• Two Types of Reproduction• Sexual and Asexual Reproduction• This life processes also occurs in each

organism for repair and renewal.

• This is the only life process that is not necessary for the survival of the organism

Metabolism• Sum of all the chemical reactions

in an organism• All require energy• Sunlight is the ultimate energy

for life on Earth

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

Organization of Life• Atoms• Molecules• Organelles• Cells – life starts here• Tissues• Organs• System• Organism

Organization of Life• Population• Community• Ecosystem• Biosphere