Needs of Living Things

Characteristics of Living Things

• Cellular Organization• Uses energy• Contain Similar

Chemicals• Respond to surroundings• Reproduce• Grow and Develop

Cellular Organization• All living things are

composed of cells• Unicellular – single-

celled organisms (ex. Bacteria)

Cellular Organization• Multicellular –

organisms that are composed of more than one cell (ex. Humans)

Chemicals of Life• All living things

contain similar chemicals

• The most abundant chemical in cells is water

Use Energy• All living things use

energy to do the things that living things must do (ex. Grow and repair injured parts)

Growth and Development• Growth is the process of

becoming larger• Development is the

process of change that occurs during an organism’s life to produce a more complex organism

• A Response is when a living thing reacts to stimuli

• Stimuli is a change in your surroundings

Response

Response• All living things

respond to stimuli• Living things respond

in different ways• The ways in which

living things respond is called behavior

• Migration to warm places in a response

• Hibernation (sleeping) through the winter months is another example

Response

Reproduction• Reproduction is the

process by which living things produce new organisms (offspring) like themselves.

Spontaneous Generation

• Spontaneous Generation is the idea that living things come from nonliving things.

• Francesco Redi disproved this theory.

What Do Living Things Need?

• Water• Energy• Living Space• Stable Internal

Conditions

Water

• Plants & animals cannot survive without water

Water• Water is used to

transport stuff through living things

• Water is necessary to carry out chemical changes in living things

Energy• All energy comes from

the sun • Autotrophs (organisms

that make their own food) get their energy directly from the sun

Energy• Heterotrophs

(organisms that cannot make their own food) get their energy indirectly from the sun

Living Space• Living space includes

air, water, sunlight, food, and shelter

• Organisms need living space to survive

• Organisms compete for living space

• Proper temperature is necessary for living things to carry out life processes

• Many living things would die without homeostasis

Stable Internal Conditions

Stable Internal Conditions

• Homeostasis is the ability of a living thing to keep conditions inside its body constant

Stable Internal Conditions

• Homeostasis keeps life processes working even if external temperature changes

What are Life Processes?

• Life processes are the things an organism must do to stay alive

• Living things carry out all life processes

Life Processes• Ingestion• Digestion• Respiration• Excretion

Life Processes• Ingestion

–taking in food• Digestion

–breaking food down so it can be used

Life Processes• Respiration

–using oxygen to get energy from food

• Excretion–getting rid of waste