Download We all have these in common.

We all have these in common.
8 Characteristics of Life
Living things share 8 characteristics:
1. Living things are made up of units called
cells.
a. Every organism is composed of at least
one cell.
1.) single-celled or unicellular
2.) many-celled or multicellular
b. There are two broad categories of cells:
1) prokaryotic—no organized nucleus nor
membrane bound organelles; found in bacteria
and cyanobacteria
2) eukaryotic—do have an organized nucleus and
membrane-bound organelles such as Golgi
apparatus and mitochondria. All other
organisms such as plants and animals have this
kind of cell.
2. Living things reproduce.
There are two basic kinds of reproduction:
a) Asexual—only one parent and all offspring are
identical; for example, binary fission of bacteria
or amoebas.
b) Sexual—two cells from different parents unite
to produce the first cell of a new organism.
3. Living things are based on a universal genetic
code (DNA).
a) The directions for inheritance are found
in deoxyribonucleic acid or DNA.
b) The genetic code is basically the same for
all organisms on Earth.
4. Living things grow and develop.
a) For single-celled organisms, growth is
mostly an increase in size.
b) Multicellular organisms go through a
process called development, where cells
divide and differentiate into different
kinds of cells.
5. Living things obtain and use materials and energy.
a) The combination of chemical reactions through
which an organism builds up or breaks down
materials as it carries out its life processes is called
metabolism.
b) Autotrophs (also called producers)—plants, most
algae, and some bacteria obtain their energy
directly from the sun through photosynthesis.
c) Heterotrophs (also called consumers)—most other
organisms, rely on the energy stored during
photosynthesis.
1. Herbivores—eat plants and other photosynthesizing
organisms
2. Carnivores—eat the herbivores or other carnivores
3. Omnivores—eat both plants and animals
4. Decomposers—such as bacteria and fungi; obtain
energy from the remains of organisms that have
died
6. Living things respond to
their environment.
a) Organisms detect and
respond to stimuli from
their environment.
b) A stimulus is a signal to
which an organism
responds.
c) External stimuli include
temperature and light.
d) Internal stimuli come
from within, such as
blood sugar level or
feeling thirsty.
7. Living things maintain a
stable internal
environment.
a) Even though external
environmental conditions may
vary widely, most organisms
must keep internal conditions,
such as temperature and
water content, fairly constant.
b) Maintaining a stable internal
environment is called
homeostasis (Greek, same
condition).
8. Taken as a group, living things change over
time (living things evolve).
a) Plants have adapted to living in dry and hot
deserts.
b) Fossils of ancient organisms can be used to
show how organisms have changed over
time.