Carrying Out Life
Processes
EQ: How are life processes carried out by
unicellular and multicellular organisms?
Life Processes
O A process is a series of
steps taken to achieve an
outcome.
O All organisms perform
certain processes to
obtain oxygen, obtain
food, to remove wastes,
and to grow.
O Photosynthesis, cellular
respiration, diffusion,
osmosis, mitosis are all
life processes carried out
by all organisms
Unicellular vs. Multicellular
O An organism can be
defined as living being
that shows all six of
the characteristics of
life.
O Growth, reproduction,
responds to
environment, uses
energy, composed of
cells, has DNA
Unicellular Organisms
O Some living organisms
are made of one cell only,
and are called
unicellular.
O These organisms have a
large surface area to
volume ratio and rely on
simple diffusion to meet
their needs.
O All life processes are
performed by the
organelles within the cell
Unicellular Organisms
O An example of a unicellular
organism is the paramecium.
O A paramecium is a small one
celled living organism that
has all six characteristics of
living things and can carry out
life processes.
O Useful substances that the
paramecium requires like
oxygen passes into to the
paramecium from the
environment by diffusion and
waste substances pass out
into the environment also via
diffusion.
Multicellular Organisms
O Multicellular organisms are
those which are made up of
many cells.
O Humans are multicellular.
O Multicellular organisms can
be much larger and more
complex.
O This is because the cells of
the organism have
specialized into many
different types of cells such
as nerve cells, blood cells,
muscle cells all performing
different functions.
Multicellular Organisms
O Furthermore, the
specialized cells
make up tissues,
tissues make up
organs, and organs
make up organ
systems.
O OCTOSO
Unicellular vs. Multicellular
Unicellular
O Simple body construction
O
O
O
O
O
(single cell)
All functions carried out by
the organelles of the single
cell
Does not achieve large size
Short life span
No cell specialization
Tend to be microscopic
Multicellular
O Complex organization
O Specific functions for
O
O
O
O
different cells
Cell specialization,
Can increase size by
increasing the number of
cells
Longer life span
Tend to be macroscopic
(seen with naked eye)
Unicellular
Multicellular
Balancing The
Systems
EQ: How do organ systems work together
to enable an organism to maintain
homeostasis?
Systems
O A group of organs
that work together
and provide an
organism with an
advantage for
survival is called a
system.
Systems
O Systems are the most
complex organizational
level in your body.
O OCTOSO
O Systems are made of
individual organs, such
as the heart or lungs
O Systems work alone
and with other systems
to allow your body to
maintain homeostasis
Examples of systems in the
human body:
O Circulatory
O Excretory
O Skeletal
O Integumentary
O Muscular
O Nervous
O Respiratory
O Lymphatic
O Digestive
O Endocrine
Homeostasis
O https://www.youtube.co
m/watch?v=QKT47ALBj4
O Homeostasis is a stable
internal environment that
allows you (and your cells
to survive)
O All of your body’s systems
work together to
maintain homeostasis
inside your body
Homeostasis
O Homeostasis is
achieved by making
sure the
temperature, ph
(acidity), oxygen
levels, and many
other factors are set
just right for your
cells to survive.
Your systems must work together to
achieve homeostasis
O All systems in an organism
are interconnected.
O For example: the
circulatory and respiratory
systems
O As blood circulates
through your body, it
needs fresh oxygen from
the air.
O When the blood reaches
the lungs, part of the
respiratory system, the
blood is reoxygenated.
Today’s task
O You will be placed in a small group and
assigned an organ system.
O You are to use the packets provided to find
the following information so that we may
complete the graphic organizer on the board
O Major organs of the system
O The purpose/functions of the system
O How your system interacts with other systems
O Other critical information