the cell theory and homeostasis. the cell theory with the invention of the microscope and the help...
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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
• 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• 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
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
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:– 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
System Function Diagram Major Organs
Interactions with Other Systems
Digestive
1. take in food (ingestion)
2. digest food into smaller molecules
and absorb nutrients
3. Remove undigestable food from body (feces)
Mouth, esophagus,
stomach, Sm.Intestine, Lg.
intestine,rectum, anus
Salivary glands
1. w/circulatory – absorb & deliver the digestednutrients 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.
RespiratoryTakes in oxygen
and removes carbon
dioxide and water
NoseTracheaBronchi
BronchiolesAlveolilungs
1. w/circulatory – takesin O2 for delivery to cells
and removes CO2 brought from cells
2. w/excretory – removesexcretory waste
3. w/nervous – controlsbreathing
4. w/muscular – diaphragm controls Breathing
System Function Diagram Major Organs
Interactions with Other Systems
Circulatory Transport
materials to and from cells
HeartVeins
ArteriesCapillariesRed blood
cells
1. w/respiratory – deliver O2 from lungs to cells and drop off
CO2 from cells to lungs2. w/digestive – absorb anddeliver digested nutrients to
cells3. w/excretory – kidneys filter cellular waste out of blood for
removal4. w/lymphatic – both transport
things to and from cells5. w/immune – transports
WBCs throughout body to fight disease
6. w/nervous – brain controlsheartbeat
7. w/endocrine – trans. Hormones
Reproductive
Allows organisms to
reproduce which
prevents their species from
becoming extinct.
Ovaries*produce
eggs
Testes*produce
sperm
1. w/endocrine – controlsproduction of sex cells2. w/muscular – uteruscontracts to give birth –controlled by hormones
System Function Diagram Major Organs Interactions with Other Systems
Excretory
1. removes waste
products fromcellular
metabolism (urea,
water, CO2)2. filters blood
KidneysUretersBladderUrethra
1. w/circulatory – filters waste out of blood
2. w/lungs –removes excretory waste
3. w/integumentary – removes excretory waste
ImmuneFights off foreign
invaders in thebody
White BloodCells
*T cells*B cells
-produceantibodies
*MacrophagesSkin
1. w/circulatory –transports WBCs to
fight invaders2. w/lymphatic – has lots
of WBCs to fightinvaders, spleen filtersbacteria/viruses out of
blood3. w/skeletal – WBCs
made in bone marrow4. w/integumentary –
prevents invaders fromgetting in
Nervous
1. gathers andinterprets
information2. responds to
information3. helps maintain
homeostasis
BrainSpinal cord
NervesNerve cells =
neuronshypothalamus
Controls all othersystems
Hypothalamus – maintains
homeostasis by workingwith all systems
System Function Diagram Major Organs Interactions with Other Systems
Muscular Allows for
movement bycontracting
Cardiac muscleSmooth muscleSkeletal muscle
tendons
1. w/skeletal – allowmovement
2. w/digestive – alloworgans to contract to
push food through3. w/respiratory –
diaphragm controlsbreathing
4. w/circulatory – controls pumping of
blood (heart)5. w/nervous –
controls all muscle contractions
Skeletal
1. protects organs2. provides shape,
support3. stores materials
(fats, minerals)4. produces blood
cells5. Allows
movement
BonesCartilageligaments
1. w/muscular – allowmovement
2. w/circulatory –produce blood cells
3. w/immune – produce white blood
cells4. w/circulatory and
respiratory – protectsit’s organs
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