Grade 10 Cells and Cell Specialization Review Free Essays

Cells, Cell Division, and Cell Specialization Fundamentally Different Types of Cell Prokaryotic Cell- single celled: only DNA+ structure (â€Å"before nucleus†) E. g. zygote-complete DNA Eukaryotic Cell-multi-celled (â€Å"after nucleus†) ProkaryotesEukaryotes DNAIn â€Å"nucleoid† regionWithin membrane-bound nucleus ChromosomesSingle, circularMultiple, linear OrganellesNoneMembrane-bound organelles SizeUsually smallerUsually larger- 50 times OrganizationUsually single-celledOften multicellular Sexual ReproductionNoneMeiosis: Combination of DMA from 2 cells 3 postulates of cell theory (Created by Schleiden, Schwann) . We will write a custom essay sample on Grade 10 Cells and Cell Specialization Review or any similar topic only for you Order Now All living things are composed of cells 2. All cells from pre-existing cells (e. g. through cell division) 3. Cells are the basic functional units of living organisms Functions of organelles OrganelleIn business termsFunctions CytoplasmPlace to work-suspends organelles -stores substances that are needed for later -many chemical reactions take place CytoskeletonPlace to work-transports vesicles and organelles -determines cell shape E. g. while blood cell: uses it to reach and swallow bacterium Ribosome/ EnzymesWorkers-makes proteins that enter the ER for modification NucleusThe boss-protects DNA chromosome: large continuous piece of DNA, containing many genes -gene: many sets of instructions on a chromosome, make functional products -nucleolus: region of DNA that codes ribosomes -nuclear pore: holes in a nuclear membrane Endoplasmic Reticulum Internal transportation-transports materials throughout the cell with its branching tubes and pockets -brain: assists with production, release of hormone -muscles: involved with muscle contraction Golgi ApparatusExports transportation-collect and process materials to be removed from the cell -make and secrete mucus Cell MembraneSecurity/ export/import-support the cell allow some substances to enter while keeping others out (semi-permeable) Chloroplasts Cash flow-absorb light energy for photosynthesis? the process of converting carbon dioxide and water in glucose and oxygen using chlorophyll MitochondriaSpender of cash-make energy available to the cell -contains enzymes? convert stored energy into a easily usable form ( cellular respiration) LysosomesWaste removal/ recycling-digestive system of cell? break down waste from both inside and outside the cell Vacuoles Storage-contain substance, removing unwanted maintaining internal turgor pressure within the cell Differentiating between plant and animal organelles AnimalsPlants Lysosome: present in all animal cells but not allCell Wall: provides structural support, prevents cells from rupturing, outside of cell membrane Centrioles: involved in cell divisionChloroplasts: absorb light energy for photosynthesis? the process of converting carbon dioxide and water in glucose and oxygen using chlorophyll Vacuole: a portion of the cell membrane may turn inside out to form a vacuole to digest the engulfed objectVacuole: controls turgor pressure, much larger Reasons who cells must divide 1. Reproduction -all cells use division to reproduce -single celled organisms: split to form new organism (asexual reproduction) -multi celled organisms: 2 parental cells combine to form new organism (sexual reproduction) 2. Growth -transport of nutrients and waste across the cell limits cell size (diffusion: from highly concentrated areas to lower concentrated areas) -movement of chemical occurs by diffusion? cells get too large, chemical and water can’t move fast -only way to get bigger and still function properly is to add more cells 3. Repair/Regeneration -needed to stay alive E. g. kin cells replaced daily, red blood cells replaced ever 120 days, breaking bones or cuts and blisters: new cells needed to fill the gaps -replaces lost cells Why do cells specialize? Cells have exact same DNA in its nucleus? location and chemical messages from other cells activate certain genes. As a result each cell has a unique function in which they must perform Types of stem cells â€Å"Undif ferentiated† Totipotent-â€Å"embryonic† stem cells E. g. zygote ?Completely undifferentiated E. g. cells from first few divisions after fertilization ? Can become any type ? Destroys the embryo when collected Pluripotent- â€Å"adult† stem cells E. g. trophoblast Already partially differentiated and located in specific body tissues E. g. bone marrow, umbilical cord ? Can become many types, but not all Multipotent ? Can only differentiate into a limited range of cell types Cancer- What and how it forms What: When genes that control the duration of interphase get mutations (random changes in DNA code) that causes a cell to grow out of control. As a result it forms a tumor (lumps of cells) that doesn’t fully differentiate or function properly, using valuable resources Tumor Types 1. Benign (non-cancerous): cells don’t interfere or invade other cells, but large masses can crowd nearby tissues 2. Malignant (cancerous): interferes or invades other cells, nearby tissues and potentially mestasize Mestasize: process of cancer cells dividing and going to other places in the body by breaking away from an invasive primary tumor, forming additional secondary tumors Causes of Cancer 1. Cellular: DNA is copied improperly during S phase of cell cycle 2. Environmental: mutations caused by carcinogens (E. g. chemicals, energy, some viruses) Methods of Screening Cancer -Pap smear (cervical cancer) -Mammogram (breast cancer) -Colonoscopy (colorectal cancer) -PSA blood test (prostate cancer) -Self-Examination Biopsy: removal of body tissue for laboratory examination (E. g. taken with endoscope) Methods of diagnosing cancer -Endoscopy: Camera and tissue extractor -X-ray: uses radiations to get images of tissues -Ultrasound: uses sound waves to create images of soft tissues -CT/Cat Scan: Computer Axial Tomography creates #. D images MRI Scan: Magnetic Resonance Imaging creates #. D image using magnetic fields and radio waves and computer analysis Different methods of treating cancer -Surgery: physically removing -Chemotherapy: treating with a series of drugs that target rapidly dividing cells -Radiation: killing cancer cells with target radiation Biophotonics: uses beams of light to detect and treat cancer Different parts of the cell cycle- Description Interphase: -period before a cell divides -longest part of the cycle (3/4 of its time) -cell grows, performs daily functions and chromosomes are duplicated S-Stage of Interphase Strands of the SNA are copied but remain attacted to the original protein Mitosis: process by which all cells divide (to divide up the DNA that has been copied and create 2 identical cells each with a complete set of chromosomes Prophase: duplicated chromosomes shorten and thicken (chromatin begins to condense by supercoiling, wrapping around protein balls -nuclear membrane starts to dissolve) -spindle fibres (made of microtubles) form -centrioles move to opposite ends (poles of the cell) Metaphase: -double stranded chromosomes line up along the equator (middle of the cell) Anaphase: -each double stranded chromosome splits and the single stranded chromosomes travel along the spindle fibres to opposite e nds of the cell -sister chromatids get pulled apart Telophase: -chromosomes reach the opposite poles of the cell and become longer and thinner -new nuclear membrane forms around each set of chromosomes -spindle fibres disappear -supercoiled DNA begins to uncoil to form chromatin again Cytokinesis: -division of cytoplasm and cellular organelles (pinching off to form individual cells) Plant cells: grow a new cell plate built with proteins to form a new membrane) Result: mother cell splits in half to form 2 daughter cells Drawing the cell cycle How to cite Grade 10 Cells and Cell Specialization Review, Essay examples