Upload
jacob-darcy-phelps
View
217
Download
0
Tags:
Embed Size (px)
Citation preview
Life Structure and Life Structure and ClassificationClassification
What are living things like?• Any living thing is an organism• Organisms • : are organized• : grow and develop• : respond• : maintain homeostasis• :use energy• : reproduce
OrganizedOrganizedAll living organisms are
composed of cellsCells are smallest unit of life that
carries on the function of lifeCells take in materials and use
them in complex waysHave orderly structure and
instruction for transfer of heriditary material
Living Things grow and Living Things grow and DevelopeDevelope
Single cell organisms increase cell size
Multi-celled organisms grow by increasing number of cells
Changes that take place during lifetime is known as development
Figure 2 shows examples of development
Life span is the length of time an organism is expected to live
Living things RespondLiving things RespondLiving things interact with their
surroundingsAnything that causes change in
an organism is a stimulus and the reaction to that is a response
Organisms must respond to stimuli to carry on daily activity and to survive
Maintain HomeostasisMaintain HomeostasisInside cells they must respond to
stimuli within (water or food levels within)
Cells internally make adjustmentsThis regulation of an organism’s
internal life maintaining conditions that is in response to it’s environment is called homeostasis
Living things use Living things use energyenergyAll energy for cells originates from
the sunPlants use sun directly to produce
energy (photosynthesis) where H2O + CO2 produces C6H12O6 (carbohydrates) and O2
Animals and some other organisms take in carbohydrates and oxygen to produce its energy
Some bacteria deep in dark ocean floors use stored energy in chemical compounds to make food
Living things must Living things must reproducereproduce
In order for an organism to continue to its own kind it must be able to reproduce itself
What do living things What do living things need to surviveneed to survive
Place to liveNeeds water
◦Water transport minerals within and between cells
◦Water is released by organisms and homeostasis is maintained
Needs food source◦Animals need to take in food, where
plants produce their own food◦Organisms die and are decomposed
by other organisms that are reused again
How are living things How are living things classifiedclassified
section 2section 2
Carolus Linnaeus◦Developed a system of organizing
organisms by similar structure in system called Binomial Nomenclature.
◦Used Scientific Names rather than common names
◦Modern classification use structure, hereditary information and early stages of development
Binomial NomenclatureBinomial NomenclatureTwo word naming system (latin
names)First word is the genus name
(contain similar species)Second word is the species
name◦Can describe a feature, place or
honor an individual◦Ambystoma tigrinum (salamander
named because of tiger stripes)Organisms of same species can
reproduce amongst themselves
Scientific NamesScientific NamesWhy they are importantWhy they are important
Help avoid confusion with common names
Organisms with similar evolutionary histories are group together
Gives descriptive information about species (tiger salamander)
It is organized efficiently
Classification OrderClassification Order
Organisms are classified in following order:◦Kingdom◦Phylum (Division in plants)◦Class◦Order◦Family◦Genus◦species
Modern ClassificationModern ClassificationToday scientist use phylogeny
to classify organisms◦Uses fossils, evolutionary history
and changes over time to classifySmallest group is a speciesBroadest group is KingdomFigure 6 in book classifies a
brottle nosed dolphin
Tools for Identifying Tools for Identifying OrganismsOrganisms
Field guides and dichotomous keys aide to identify organisms
Dichotomous key (use 2 characteristics that you choose between that leads to identification of organisms)◦The key will lead to genus-species
final name of organism
Cell StructureCell Structuresection 3section 3
Viewing cell structure◦First developed by using two
magnifying glasses together to see larger view of cells
◦Leeuwenhoek (Dutch) saw inside cells (1600’s) called them beasties
Development of Cell Development of Cell TheoryTheory
Hooke in 1665 sliced a piece of cork and saw empty space he called cells
1830 Scheiden used a microscope to study plant parts and called them cells
Schwann observed animal cellsBoth men combined their ideas and
were convinced all living things are made of cells
Mid 1800’s Virchow proposed that cells divide and every cell comes from a cell that already existed
Cell TheoryCell Theorytable 2 (page 221)table 2 (page 221)
All Cells are made up of one or more cells
Cells are the basic unit of organization in organism
All Cells come from pre-existing cells
Cell organizationCell organizationScientists divide cells that have a
membrane bound structure and those that don’t
Cells without a membrane are called prokaryote cells
Cells with a membrane around the cell are called eukaryote cells
Each cell performs specific functions but all cells must take in nutrients, store, produce and breakdown substances, take in and use energy
Structure of cells perform certain functions
Cell WallCell WallTough rigid outer coverings that
protect cells and give them shapeFound in all plants, algae, fungi
and most bacteriaPlants cell wall contain mostly
cellulose (carbohydrate) and allows water and nutrients in and out◦Pectin (found in plant cell walls) is
glue-like structure that has thick structure (jams and jellies)
◦Lignin (makes cell walls rigid) found mostly in plant cells that aide in supporting plants
Cell MembraneCell MembraneAll cells contain a cell membrane
It is the outermost covering of cells unless they have a cell wall
Regulates interactions between cells and environment
Allows nutrients to move in and wastes to leave cell
CytoplasmCytoplasmGell-like substance inside cell
membrane is called cytoplasmLife processes take place hereProkaryote cells cytoplasm contains
the hereditary materialAll organelles are located hereCytoskeleton found in cytoplasm is
made of proteins that help cell change shape, enable some cells to move
Manufacture of Proteins in Manufacture of Proteins in CellsCellsEvery cell activity involves proteinsProteins are part of cell membrane
and are part of all chemical reactions in cell
Ribosomes produce protein in cells◦Found in cytoplasm◦Get their instruction from hereditary
material that tells them how, when and in what order to make specific proteins
Membrane-bound Membrane-bound OrganellesOrganelles
Organelles are structure in cytoplasm that carry out life functions in cells
Found in cytoplasm of eukaryotic cellsNucleus is largest organelle
Ribosomes are not membrane bound but are considered an organelle
Organelles that produce Organelles that produce EnergyEnergy
Chloroplasts: (organelle found in plants)◦Contain chylorophyll (green pigments)
that captures sunlight to make sugars called glucose
◦Captured light energy is stored in glucose as chemical energy where plants utilizes glucose to carry out life functions in cells
Organelles that produce Organelles that produce EnergyEnergy
Organelle that releases energy is Mitochondria
Food (glucose and carbohydrates) is broken down into CO2 and H2O and releases energy
Sometimes called the powerhouse organelle because it provides the energy for cells
All plants and animal cells have these
Organelles that process, Organelles that process, transport and store transport and store
materialsmaterials Endoplasmic reticulum (ER) takes up considerable amount of space that process and move materials around cell like a conveyor belt
Rough ER contains ribosomes where protein is made and moved in cell
Smooth ER process lipids and oils that store energy
Organelles that process, Organelles that process, transport and store transport and store materialsmaterialsAfter proteins is made they are
transferred to Golgi bodies where they are packaged and moved to areas of cells in vesicles
Materials are also moved to outer membrane for release outside of cell
Vacuoles also are organelles that store water, waste products, food and other cell materials
Organelles that Organelles that RecycleRecycle
Lysosomes are structures that break down food molecules, cell waste, worn-out cell parts and viruses
Chemicals released from lysosomes break down food and dead cells
These chemicals are contained in lysosomes and when a cell dies, the chemicals are released and break down the dead cell
Many Celled OrganismsMany Celled OrganismsMany celled organisms rely of other cells to
perform all life functionsTissue is a group of similar cells that work
together to do one jobTissues are organized into organs.Organs are a group of tissues that work
together to perform a function (heart..nerve, blood and cardic muscle tissue)
Group of organs working together perform a certain function is an organ system
Organ systems work together to make up many celled organisms (heart, arteries, veins, and capillaries)
VirusesVirusessection 4section 4
Viruses causes many diseasesViruses are non-living strands of
hereditary material surrounded by a protein coat◦Do not have nucleus, other
organelles or a cell membraneViruses rely on host cells to live
inside (living cells)Have two kinds of viruses: Active and Latent
Active VirusesActive VirusesOccurs when virus enters host
cell and immediately begins to make new viruses
Destroys the host cells when it makes new viruses
Virus uses host cell to duplicate its hereditary material and later releases duplicated virus and kills host cell when they are released
Figure 17 page 232
Latent VirusesLatent VirusesSome viruses enter host cell and
remain inactive for a period of time
Does not immediately cause the host cell to duplicate new virus
At a later time it may begin to duplicate and release new viruses that kill the host cell
AIDS, cold sores are examples
How do viruses affect How do viruses affect organismsorganisms
Viruses attach specific cells that match host cells
Many times viruses only attach to certain host cells (potato leafroll)
Some viruses can affect numerous organisms (rabies)
Viruses are moved by wind and inhaled where they attach
Figure 18 page 233
Treating/Preventing Viral Treating/Preventing Viral DiseasesDiseases
Treatment difficult because antibiotics do not kill viruses
Prevention is best method of avoiding viral infections (eliminate mosquito to fight yellow fever)
Natural ImmunityNatural ImmunityHuman bodies fight viral
infections by making interferonsInterferons are proteins that
make a protective covering for cells that are infected (produced by healthy cells to protect affected cells)
VaccinesVaccinesVaccines are weakened viruses
that can’t enter host cells and duplicate, but cells begin to make interferons that protect all cells from infection
Measles, mumps, small pox, chicken pox, polio, and rabies
Found vaccine by taking weakened cow pox cells and entering them into healthy people to prevent small pox (1786) Jenner