Characteristics of Life
How do you know if something is alive?
A. Biology- study of life
B. Living things share 8 characteristics:
ALL LIVING THINGS MUST:
Reproduce- sexual- 2 different parents
Offspring different from parents & each other
●
asexual- one parent
offspring are a copy of parent (clone)
2. Be made of Cells- smallest living thing:
unicellular organism is made up a single cell
multicellular organisms are made up of many cells
organized into tissue, organs &
systems
Amoeba
3. Have DNA- Genetic Material
parents pass DNA to offspring
4. Grow and Develop- all organisms grow at
some point in life; some do metamorphosis
5. Respond to environment- Organisms live in
constantly changing environments and must
respond to stay alive.
Examples:
1) Days become shorter and the temperature
gets colder - Snowshoe hare changes color
2) Your body temperature goes up - you sweat
(Identify the Stimulus & the Response in these examples)
6. Evolve- as a species, living things change over
time
7. Maintain Homeostasis- keeping body normal
(temp, pulse, pH, etc.) despite external changes
“Homeo”-same
“stasis”- state
8. Have Needs for materials and energy-Organisms
must gain energy either from the sun or other
organisms to survive
●
Living things need energy to grow,
develop, repair damage, get food,
avoid danger, reproduce, etc.
● Sun – ultimate source of energy for most
life on earth
● Autotrophs (plants, algae, and many
bacteria) use the sun’s energy to make
food.
● Heterotrophs (animals, fungi, and many
bacteria) ingest other organisms for food
& energy.
So what are the 8 characteristics of
all living things??
●
●
●
●
●
●
●
●
Reproduce
Made of Cells
Have DNA—genetic material
Grow and Develop
Respond to their environment
Evolve
Maintain Homeostasis
Obtain and Use Energy