Transcript Multicellular_System..

Multicellular Organisms
Cell Teamwork:
The Processes of Life
Objectives
At the end of this PowerPoint, you will be able to:
• Explain the common problems that multicellular
organisms have.
• Identify body systems in these organisms that
allow them to function as a multicellular
organism.
• Show how these complex systems work together
to carry out the vital functions of life.
CONTENTS
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Body Organization
What Cells Need
Transportation of Materials
Obtaining Nutrients
Gas Exchange
Excretion
Movement
Control
Protection
Reproduction
Body
Organization
• At first an organism
like a human appears to
be this complicated pile
of organs.
But first, let’s
look at how life
is •Those
organized
organs make up
the organ
systems
of the
from
the
bottom
body.
up.
Levels of
Organization
Organism
Organ System
Organ
Tissue
Cell
Organelle
Molecule
Atom
How to Be a
Multicellular
Organism
Let’s look at the
difficulties in being
made up of more than 1
cell and how the body
systems are organized to
make it all work.
CONTENTS
What Cells Need
All cells, whether
alone or part of a
larger organism,
do the same
processes.
Cell
CONTENTS
Unicellular Organisms
• A protist is
surrounded by
water, food, and
oxygen.
• Materials just
diffuse in and out
of the cell.
Nutrients
Protist
Waste
Oxygen
What Cells Need
Water
• Thus all cells need
the same
materials and…
• Excrete the same
waste products.
Oxygen
Gas (O2)
Nitrogen
(proteins)
Protist
Nitrogen
Waste
Carbon
Dioxide
(CO2)
Diffusion – How Chemicals Move
Water
• A protist is
surrounded by water,
nutrients, and oxygen.
• Materials just diffuse
in and out of the cell.
Oxygen
Gas (O2)
Nitrogen
(proteins)
Protist
Nitrogen
Waste
Carbon
Dioxide
(CO2)
Diffusion – How Chemicals Move
Water
• A protist is
surrounded by water,
nutrients, and oxygen.
• Materials just diffuse
in and out of the cell.
Oxygen
Gas (O2)
Nitrogen
(proteins)
Protist
Nitrogen
Waste
Carbon
Dioxide
(CO2)
Transportation Needed
Nutrients
• In a multicellular
organism, only the
outermost cells can
exchange materials
with the outside
environment.
• These organisms
need a way to get
materials in and out
of the inner cells.
CONTENTS
Waste
Oxygen
?
Transportation Needed
• In some simple
organisms like
this sponge,
water with
nutrients just
flows in and out
of the organism.
Transportation: “Pipes”
In more
complicated
multicellular
organism, there
are “pipes” which
transport
nutrients around
the body.
Plant Transportation Systems
• In plants xylem
pipes carry water
and nutrients up
from the roots.
• Phloem pipes
carry food from
the leaf down to
other cells.
Animal Transportation Systems
In animals, blood
vessels are the pipes
that transport food,
oxygen, and wastes
around the body.
Animal Transportation Systems
We also call this system the
Cardiovascular System.
• cardio- = heart (the pump)
• -vascular = vessels (the pipes)
CONTENTS
Multicellular Organisms: Obtaining Nutrients
Food
• Multicellular
organisms (except
plants) need food
for energy.
• They need a
system to get food
in and broken up
for the body to use.
CONTENTS
Waste (unused food)
Animals: Obtaining Nutrients
Animals have a digestive
system which:
• Takes in food
• Breaks the food down.
• Gets the digested food
into the blood for
transportation to the
cells.
Plants do need:
• Sunlight for energy
Because plants make their own food through
photosynthesis, they:
• Water
• Do not eat and
• Do not need a digestive system.
• Carbon
Dioxide
• Nutrients
Plants: Obtaining Nutrients
Plants have organs which
help them take in
nutrients and to do
photosynthesis:
• Roots – Absorb (take in)
water and nitrogen from
the soil
• Leaves – take in carbon
dioxide and carry out
photosynthesis
CONTENTS
• Take in CO2
• Location of
photosynthesis
• Absorb water
• Absorb nitrogen
Multicellular Organisms: Gas Exchange
Oxygen CO2
• Multicellular
organisms need a
system to get
oxygen in and
carbon dioxide out
of the body.
CONTENTS
Plants: Gas Exchange
Plants also need to
exchange gases with
the atmosphere.
LEAF
For Photosynthesis:
CO2 in
O2 out
For Cellular Respiration:
O2 in
CO2 out
CO2 in
In
Photosynthesis
O2 out
Plants: Gas Exchange
Plants also need to
exchange gases with
the atmosphere.
LEAF
For Photosynthesis:
CO2 in
O2 out
For Cellular Respiration:
O2 in
CO2 out
CO
O
2 in
2 in
CONTENTS
In
Respiration
O2 out
CO
2 out
Multicellular Organisms: Excretion
• Multicellular
organisms need a
system to get
poisonous wastes
out of the body.
CONTENTS
Waste
Multicellular Organisms: Excretion
• Removing carbon
dioxide (CO2) from
the body is also part
of excretion.
CO2 out
Excretory System
We sometimes combine these 2 systems under the
heading of the Excretory System.
Excretory
System
=
Urinary
System
+
+
CONTENTS
Respiratory
System
Unicellular Organisms: Movement
• For a protist to
move, it simply
needs to move its
one cell.
CONTENTS
Protist
Multicellular Organisms : Movement
• A multicellular
organism can only
move if every cell
moves at the same
time and in the same
direction.
• A control system is
needed for this to
happen.
CONTENTS
Multicellular Organisms: Control
• A multicellular
organism needs to
have control systems
to coordinate cells.
CONTENTS
Electrical Control: Nervous System
• Central Control – Brain and Spinal Cord
• Nerves to carry messages
PLANTS
Sorry, no answer here.
Discuss this one with your group.
Chemical Control: Endocrine System
• Glands produce chemical hormones.
• The blood carries these chemical messages.
That’s right. The Circulatory System
The blood is needed to transport the
chemical hormones around the body.
CONTENTS
PROTECTION
• Multicellular organisms, like unicellular
organisms, need protection.
• This protection or defense is the combined
effort of many systems.
• Cells work together as a tissue, organs work
together in a system, and the systems work
together to protect the organism.
CONTENTS
PROTECTION
• Your bones and cartilage
protect organs.
• Your bones make up an
endoskeleton (inside).
• Many animals have an
exoskeleton (outside).
The horseshoe
crab’s shell is
an exoskeleton.
PROTECTION
• Your muscles aid in
protection in allowing
you to escape.
PROTECTION
• These 2 systems allow
you to sense, react and
escape danger.
PROTECTION
Organisms have skin and
often other protective
coverings.
PROTECTION
• The circulatory system
transports the food and
oxygen that you need for
dealing with emergencies.
• Your blood’s ability to
clot is protection from
both blood loss and
harmful pathogens.
PROTECTION
But the Immune System
allows your body to fight
off pathogens (outside
invaders) that actually
enter your body.
PROTECTION
An army of different types
of white blood cells
destroy these foreign
pathogens and give you
immunity (protection)
from future “invasions”.
CONTENTS
PLANT PROTECTION
What are some of the
organs that plants have
to protect themselves?
Odor
Skunk Cabbage
What else can you think of?
CONTENTS
Reproduction
• All life can reproduce because every cell has DNA.
• Most multicellular organisms reproduce sexually by
combining an egg with either a sperm or pollen.
• These two half cells have 1/2 the DNA of each parent
and combine to form a whole cell.
CONTENTS
Plant Reproduction
• Plants, like animals, reproduce sexually.
Flowers produce pollen which fertilize eggs to
create seeds.
• Either wind or insects carry the pollen to
another flower.
Reproduction
• But some multicellular organisms can
reproduce asexually.
• Fungi produce spores which unlike eggs, sperm,
and pollen contain a complete set of DNA. Only
one parent is needed.
CONTENTS