Characteristics of Life

So, what is ALIVE?

6 CharacteristicsThere are certain characteristics that all forms

of life share. To be classified as “LIVING” the following must be present:

• Organized• Grow and develop

• Reproduce• Respond to a stimulus

• Maintain certain internal conditions• Energy

• Only those things that have all 6 characteristics of life are living.

• Things that have all characteristics of life are called

ORGANISMS

Living Things are Organized• Whether an organism is made of one cell or

many cells, all living thing have structures that have specific functions

• Some living things contain only a single cell– These single-celled organisms are called

UNICELLULAR– They perform all the functions necessary for life

• Most living things are MULTICELLULAR– They contain two or more cells. Some have

hundreds, thousands, or even trillions of cells. Humans have approximately 6 trillion cells.

Living Things Grow and Develop

• Increase in size• Development• LIFE SPAN: the

maximum length of time a particular organism can be expected to live.

Living Things ReproduceThe process by which living things make more of the same type of living thing:

• Sexual Reproduction/two parents

• Asexual Reproduction/one parent

Living Things Respond to Their Environment

• Stimuli=any change in the environment of an organism that produces a response by that organism.– Internal: hungry, thirsty– External: light, temperature

• Response= an action, movement, or change in behavior of the organism.

Homeostasismaintain certain internal conditions

• Homeostasis: an organism’s ability to maintain steady internal conditions when outside conditions change.

– It ensures that cells can function, otherwise they may die.

• Methods of homeostasis– There is a limit to the amount of change that can occur

within an organism

Living Things Use Energy

The cells of organisms use energy to do what living things must do.

Energy is used when…

• Metabolism=the sum total of all the chemical reactions that occur in a living thing

• Ingestion=take in/or produce their food• Digestion=the process by which food is

broken down into simpler substances• Respiration=the process by which living

things take in oxygen and use it to produce energy

• Excretion=the process of getting rid of waste material

Homework

• Read pages 9-15

• Copy the table 1 page 15 into NB by hand. You may draw or cut out pictures. You may also use the computer to type table out and cut & paste pictures

• YOU MAY NOT JUST PHOTO COPY THE PAGE!!