Transcript PPWhat is Life1314

CHARACTERISTICS OF LIVING
THINGS
There are six characteristics that all
living things share:
1. Made of Cells
2. Require Energy
3. Grow & Develop
4. Respond to Stimulus
5. Reproduce
6. Composed of certain chemicals
CELLULAR ORGANIZATION
• Cells are the basic building blocks of
life…of it’s alive…it’s made of cells.
• Every living thing is composed of one or
more cells.
• Organisms (that’s a living thing) can be
single-celled or made of many cells.
• Viruses aren’t made of cells…guess
what…they’re not alive. Too bad for
them…they can’t get into the movies or
play the drums…as far as I know anyway.
USE ENERGY
• Metabolism is the term that refers to all of
the activities that go on within a single cell
or an entire organism.
• Energy is required in order to carry out all
of these cellular activities.
• Metabolic processes include making food,
breaking down food, moving materials in
and out of cells, and building cells and their
components (parts). It’s a lot of
work…teenaged cells are lazy…look for
them on the couch watching TV…tragic 
GROW AND DEVELOP
• All living things grow at some period of
their lives.
• Unicellular (single-celled) organisms
simply grow larger.
• Multi-cellular organisms (made of many
cells) grow by increasing their number of
cells.
• Many organisms go through stages of
development. Some just a few…others
have many.
RESPONSE TO STIMULUS
• All living things encountering a change in
their environment will respond to that
change.
• Some responses are drastic and some are
more subtle…you can’t even see it happen.
• If you hear a loud noise you might
jump…BOO! See…calm down now. That’s a
response.
• A plant might grow toward a light
source…that’s a response too, but you can’t
see it happening. Go ahead try to frighten
a plant…it’ll ignore you and you’ll just look
silly.
• A stimulus can be: gravity, light, chemicals,
vibration, sound, temperature, electricity, etc.
REPRODUCE
• All organisms make other
organisms like themselves.
• Some living things reproduce
asexually, others
sexually…some…both…no kidding!
• Asexual Reproduction – single
parent produces offspring
(fission, budding). Offspring is
genetically identical to the
parent.
• Sexual Reproduction– two parents
required for reproduction
(conjugation) and offspring are a
combination of genetic material
from both.
MADE OF Certain Biological
Molecules (CHEMICALS)
1. Carbohydrates – made of sugars, used for energy
2. Proteins-made up of amino acids. Some are
structural (for building) and some are enzymes
(needed for chemical reactions).
3. Lipids, fats, and oils – long-term energy storage
and cell membrane construction
4. Nucleic Acids (DNA & RNA)– provide the cell’s
genetic instructions; also needed to make proteins.
5. Starburst (Cherry only)- needed to rot your teeth
and make you all hyper from too much
sugar…seriously…why are you writing this down?
If We Decide You’re Alive…Then
What?
• Well…you’ll (any organism actually) need
four basic things:
1. Water: Almost ever living thing consists of
about 70% water. It’s needed for most
chemical reactions that take place within
an organism…and there are A LOT of
them…reactions, that is 
2. A Source of Energy: These are called
nutrients (some of those chemicals we talked about).
You can make your own (if you’re an
autotroph…such as most plants), or…you can eat
another organism…your choice. Well…not really.
3. Maintain Homeostasis: Wow! That’s a big
word! So, basically it means that organisms
maintain their internal conditions (like
temperature, respiration, blood pressure…in
vertebrates). So like, if your body is hot…you
sweat and that cools you off (that’s a simple
example).
4. Physical Space: All organisms need
someplace to exist. Don’t confuse this with
“shelter!” There are plenty of living things
that live in some crazy rough places like The
Dead Sea, deserts, The Poles, boiling hot
springs, and deep sea hydrothermal vents.
Those are some crazeeee conditions and
shelter? That just ain’t happenin’
So…there you have it…
6 Criteria for Living Things and 4 Basic
Needs