https://www.youtube.com/watch?v=4_r608nDoqo

CHARACTERISTICS OF LIFE

BIOLOGY: the study of life

Biotic

Abiotic

Life is difficult to defineBiologists focus on how life worksLife is determined by a set of characteristics

that distinguish all living organisms from inanimate objects

ALL LIVING THINGS ARE MADE UP OF

CELLS

• Cells are the smallest unit of life

• Cells are the smallest unit capable of sustaining life

• Organisms range from unicellular to multicellular

ALL LIVING THINGS CONTAIN

DNA

• Organisms store, use, and transmit information to live, grow, and reproduce

• Universal genetic code

ALL LIVING THINGS

REPRODUCE

• Produce offspring similar to themselves

• Pass on genetic information

ALL LIVING THINGS

GROW and DEVELOP

• Grow in size• Change in appearance and

abilities

ALL LIVING THINGS

OBTAIN AND USE ENERGY

• Organisms require energy to perform their processes

• Obtained from their environment

• Metabolism:The combination of chemical reactions where an organism builds up and breaks down materials

ALL LIVING THINGS

RESPOND

• Organisms detect and respond to stimuli from their environment

ALL LIVING THINGS

MAINTAIN HOMEOSTASIS

• Organisms maintain a fairly stable internal environment

• Positive and negative feedback loops

ALL LIVING THINGS

CHANGE OVER TIME

• Populations change over long periods of time

• Each species has characteristics that vary within the population

• Some of these variations are preferred and become more pronounced over time

Living organisms must possess all of these characteristics simultaneously.

Inanimate systems – such as viruses – may produce most of these

ALL OR SOME?