Chapter 3 lesson 2 Life Science Presented by Mrs. Waterbury Parameciu m
Jan 19, 2016
Chapter 3 lesson 2
Life Science
Presented by
Mrs. Waterbury
Paramecium
Life’s Organization
Matter is made of atoms – Combined atoms = moleculesCells (living things only) are made of moleculesMulticellular organisms can be made up of trillions of cells Cells working together enable organisms to function – cells have specific jobsUnicellular organisms (ex amoeba, algae) – one cell carries out all activities so it can survive (eat, eliminate waste, reproduce)
Types of cells
Types of Cells:
1) prokaryotic – no membrane bound nucleusSmaller and have fewer cell structuresExample: bacteria2) Eukaryotic – have nucleusSpecialized organellesEx: all plant and animal cells (multicellular) and many unicellular organisms like algae and fungus
Cell Differentiationcells become specialized
Fertilized eggDivides through mitosisThese first cells can become any type of cell (stem cells)All the organisms info is contained in the DNA found in the chromosomesAll cells contain all the infoHowever different cells use different parts of the instructions –activates the part that codes for that cell’s specific functions
Animal stem cells
Unspecialized cells that are able to develop into many different cell typesEmbryos – many stem cellsAdults – fewer – used for cell repair and replacementEx bone marrow – produce many types of blood cellsSkeletal muscles – repair torn muscles
Plant stem cells - MERISTEMS
Unspecialized cells grouped together
Found in tips of roots and stems
Cell division in these areas (mitosis) produces diff types of specialized cells
Cell organization
Similar Cells working together to do a certain job form tissues4 main types of animal tissues – muscle, connective, nervous, and epithelial
Animal Tissues
Muscle – movement
Connective – structure and support; connects other tissues
Nervous – carries messages to and from brain
Epithelial – protective layer – skin – lining of organs
Plant tissues
Dermal – protection & helps reduce water lossVascular – transports water and nutrientsGround – storage and support; where photosynthesis takes place
Organs
Different tissues working together to perform a job - organsEx stomach – specialized to break down food made up of all 4 tissues Muscle (contracts), epithelial (lines), nervous (sends message when full), connective (supports stomach wall)
Plant organs
Leaves – job is photosynthesis – makes food
Has all 3 plant tissues
Dermal (covers), ground (produces food – site of photosynthesis), vascular (moves the food)
More organ systems
Endocrine – (growth & homeostasis) – pituitary gland, thyroid, pancreas etcRespiratory – lungs, trachea, noseUrinary – kidneys, bladder, ureters, urethraIntegumentary – protects – skin, hair, sweat glandsSkeletal – bones, ligaments, cartilage
Organ systems
Group of organs working together to complete a series of tasksDigestive - stomach, sm. Intestine, liver, and large intestineCirculatory – heart, arteries, veinsReproductive – ovaries, uterus, vagina, testes, scrotum, penis
Plant organ systems
2 major systems
Shoot system – leaves, stems, and flowers
Transports water and food
Root system – anchors, and takes in water and minerals
Organisms
Usually have many organ systems
Systems work together so the organism can survive
Organ systems depend on one another and can not function without the other
Cells differ in size, shape, and the jobs they do!
Each cell has a job to do to keep the factory running properly! Cells depend on other cells.
Cell organization
Cells working together to do a certain job form tissuesDifferent tissues working together form organsEx heart = blood, nerve, and muscle tissuesOrgans working together form organ systems
Sexual ReproductionSex cells from two parentsFertilization – egg and sperm uniteFertilized egg - zygoteHuman cells have 46 chromosomesHorses have 60Each kind of organism has a different number of chromosomesHow many chromosomes does a sex cell have ?
Egg
Female
Large
Food materials
Sperm
Male
Small –whiplike
Head –almost all nucleus
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