Transcript Review PPT – Life Science – Cells and Human

The cell theory and homeostasis
The cell theory
• With the invention of the microscope and the
help of many different scientists, a very
important questions was answered in the
1850’s:
WHERE DO CELLS COME FROM?
The cell theory
• There are 3 concepts to the cell theory:
– Every living thing is made up of one or more cells
– Cells are the smallest unit of life
– All cells come from preexisting cells
Every living thing is made up of one
or more cells
• There are two types of cells:
– Prokaryotic
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First cell to evolve
No nucleus
DNA (genetic information) contained in the cytoplasm of the cell
Growth is usually through the expansion of the cell
Examples: Archaea and Bacteria
– Eukaryotic
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Evolved from prokaryotes
Have a nucleus
DNA contained within the membrane-bound nucleus
Growth is usually through an increase in number of cells
Examples: Animals, Protists, Fungi, Plants
Every living things is made up of
one or more cells
• Prokaryotes are unicellular. This means that all
functions of life happen within that one cell
• Eukaryotes are unicellular (protists) and
multicellular. If the organism is multicellular,
different cells have different jobs and they all work
together to perform the functions of life
• Both unicellular and multicellular organisms follow
the 6 characteristics of life
The functions/characteristics
of life
• Organization
– Living things have specialized structures with specialized functions
• Growth and Development
– When organisms grow, they increase in size (unicellular) or number of
cells (multicellular). Changes that occur in an organism during its
lifetime are called development.
• Reproduction
– The process by which one organism makes one or more new
organisms
– Not all organisms of a species must reproduce in order for the species
to survive (only some need to)
The functions/characteristics
of life
• Response to Stimuli
– When an organism responds to changes in its internal or external
environment
– Internal stimuli are responses to needs within the body (hunger, aches,
etc.)
– External stimuli are responses to needs outside of the body (fear, sunlight,
etc.)
• Homeostasis
– An organism’s ability to maintain steady internal conditions when outside
conditions change
• Use of Energy
– Cells continuously use energy to transport substances, make new cells,
and perform chemical reactions.
– People use energy for everyday tasks like sleeping, eating, etc.
• Things that have all the characteristics of life are called organisms
The cell organelles
organelles
• The size and shape of a cell relates to its job or
function
• A cell is made of different structures that
perform different functions and keep a cell
alive. These structures also have unique
functions
• Organelles are tiny membrane-bound
structures that perform special functions in
the cell
Cell wall
• Only found in
plant, fungi,
bacteria, and some
protist cells
• Rigid and strong to
hold the cell’s
shape
• Provides support
and protection for
the cell
Cell/plasma membrane
• Found in all cell types
– In plant cells, it lies
beneath the cell wall
– In animal cells, it is the
outer boundary
• Provides the cell with
– Protection
– Control of the
movement of
materials in and out of
the cell
– Support
– Maintains the internal
conditions of the cell
nucleus
• Found in both
plant and
animal cells
• Consists of the
nuclear
membrane,
nucleoplasm,
and nucleolus
• Controls cell
activities and
contains DNA
• The nucleolus
makes
ribosomes
Cytoplasm and the Cytoskeleton
• Found in both
plant and animal
cells
• Cytoplasm is
thick, jelly-like
substance located
beneath the cell
membrane that
supports and
protects the cell’s
organelles
• The cytoskeleton
gives the cell its
shape and helps
it move
Golgi apparatus
• Found in both
plant and animal
cells
• Looks like a
flattened stack of
pancakes
• Processes and
packages
molecules made
by the cell for
transport around
the cell or out of
the cell in
vesicles
ribosomes
• Found in both
plant and
animal cells
• Can be found
attached the
endoplasmic
reticulum or
floating free in
the cytoplasm
• Produces
proteins
• The smallest
organelles
Endoplasmic reticulum
• Found in both plant
and animal cells
• Network of tubes
that transports
materials
throughout the cell
• Two types:
– Smooth ER (no
ribosomes)
• Makes lipids and
removes
harmful
substances
– Rough ER (has
ribosomes)
• Site of protein
production
mitochondria
• Found in both
plant and animal
cells
• Breaks down
sugar molecules
to release energy
for the cell to use
• Known as the
“powerhouse” of
the cell
• Has inner folds
called cristae to
increase its
surface area
vacuoles
• Found in both plant
and animal cells
– In plant cells, there
are very few of
them but they are
very large
– In animal cells,
they have very
many little ones
• They are fluid-filled
sacs that store food,
water, and waste
lysosomes
• Found only in
animal cells
• Break down
larger food
molecules into
small food
molecules
• Digest old cell
parts
chloroplasts
• Found only in
plant cells
• Green in color
because of
chlorophyll
• Use energy from
the sun to make
food for the plant
Levels of life’s organization
It all adds up
• All matter is composed of atoms and atoms
combine to form molecules
• All living organisms are made of cells (which
are composed of molecules)….but how do
those cells make organisms?
• Cells build together to make tissues
– Tissues build together to make organs
• Organs build together to make organ systems
– Organ systems build together to make organisms
Cells build together to make tissues
• The process by which cells become
different types of cells is called cell
differentiation
• In multicellular organisms, similar types of
cells are organized together into groups.
• Tissues are groups of similar types of cells
that work together to carry out a specific
task
Types of tissues
• Humans have four types of tissues:
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Muscle – causes movement
Connective – provides structure and support
Nervous – carries messages to and from the brain
Epithelial – forms the protective outer layer of skin
and lining of major organs
• Plants have three types of tissues:
– Dermal – provides protection and prevents water loss
– Vascular – transports water and nutrients
– Ground – provides storage and support; where
photosynthesis takes place
Tissues build together to make
organs
• Complex jobs in the body require the use of
more than one type of tissue
• Organs are groups of tissues working together
to perform a particular job
• Organs usually involve all four types of tissues
in humans and all three types of tissues in
plants
Organs build together to make
organ systems
• Organs do not usually function alone
• Organ systems are groups of different organs
that work together to complete a series of
tasks
• Humans have 11 different organ systems in
their body and plants have 2
Organ systems build together to make
organisms
• Multicellular organisms usually have many
different organ systems that work together to
perform daily life tasks that are needed for the
survival of that organism
Human Body Systems
System
Digestive
Respiratory
Function
1. take in food
(ingestion)
2. digest food into
smaller molecules
and absorb
nutrients
3. Remove
undigestable food
from body (feces)
Takes in oxygen
and removes carbon
dioxide and water
Diagram
Major
Organs
Interactions with
Other Systems
Mouth,
esophagus,
stomach, Sm.
Intestine, Lg.
intestine,
rectum, anus
Salivary glands
1. w/circulatory – absorb &
deliver the digested
nutrients to the cells
2. w/muscular – control the
contractions of many of the
digestive organs to pass food
along
3.w/nervous –hypothalamus
maintains homeostasis by
triggering appetite (stomach
growling), digest.
Nose
Trachea
Bronchi
Bronchioles
Alveoli
lungs
1. w/circulatory – takes
in O2 for delivery to cells
and removes CO2 brought
from cells
2. w/excretory – removes
excretory waste
3. w/nervous – controls
breathing
4. w/muscular – diaphragm
controls Breathing
System
Circulatory
Function
Transport
materials to
and from cells
Allows
organisms to
reproduce
which
Reproductive
prevents their
species from
becoming
extinct.
Diagram
Major
Organs
Interactions with
Other Systems
Heart
Veins
Arteries
Capillaries
Red blood
cells
1. w/respiratory – deliver O2
from lungs to cells and drop
off CO2 from cells to lungs
2. w/digestive – absorb and
deliver digested nutrients to
cells
3. w/excretory – kidneys filter
cellular waste out of blood for
removal
4. w/lymphatic – both
transport things to and from
cells
5. w/immune – transports
WBCs throughout body to
fight disease
6. w/nervous – brain controls
heartbeat
7. w/endocrine – trans.
Hormones
Ovaries
*produce
eggs
Testes
*produce
sperm
1. w/endocrine – controls
production of sex cells
2. w/muscular – uterus
contracts to give birth –
controlled by hormones
Major Organs
Interactions with
Other Systems
Kidneys
Ureters
Bladder
Urethra
1. w/circulatory – filters waste
out of blood
2. w/lungs –removes
excretory waste
3. w/integumentary –
removes excretory waste
Immune
Fights off
foreign
invaders in the
body
White Blood
Cells
*T cells
*B cells
-produce
antibodies
*Macrophages
Skin
1. w/circulatory –
transports WBCs to
fight invaders
2. w/lymphatic – has lots
of WBCs to fight
invaders, spleen filters
bacteria/viruses out of
blood
3. w/skeletal – WBCs
made in bone marrow
4. w/integumentary –
prevents invaders from
getting in
Nervous
1. gathers and
interprets
information
2. responds to
information
3. helps
maintain
homeostasis
Brain
Spinal cord
Nerves
Nerve cells =
neurons
hypothalamus
Controls all other
systems
Hypothalamus –
maintains
homeostasis by working
with all systems
System
Function
Excretory
1. removes
waste
products from
cellular
metabolism
(urea,
water, CO2)
2. filters blood
Diagram
System
Function
Muscular
Allows for
movement by
contracting
Skeletal
1. protects organs
2. provides shape,
support
3. stores materials
(fats, minerals)
4. produces blood
cells
5. Allows
movement
Diagram
Major Organs
Interactions with
Other Systems
Cardiac muscle
Smooth muscle
Skeletal muscle
tendons
1. w/skeletal – allow
movement
2. w/digestive – allow
organs to contract to
push food through
3. w/respiratory –
diaphragm controls
breathing
4. w/circulatory –
controls pumping of
blood (heart)
5. w/nervous –
controls all muscle
contractions
Bones
Cartilage
ligaments
1. w/muscular – allow
movement
2. w/circulatory –
produce blood cells
3. w/immune –
produce white blood
cells
4. w/circulatory and
respiratory – protects
it’s organs