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Download unit 5 cell reproduction
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Cellular Reproduction Section 1: Why do cells divide? • Cell reproduction is important for: Growth of our body – ____________________________ Repair damaged cells – ____________________________ DNA survival machines •Living organisms are “__________________” for _____ molecules Deoxyribonucleic acid or DNA molecules carry the –_____________________ protect and information that enables host cells to _________ ___________ maintain an organism's survival Section 1: Why do cells divide? genome • Each cell contains its own _____________ – Which is a complete collection of an organism’s ___________ information as linked ___________ in one genetic genes or more long strands of DNA • __________ provide information for building genes _____________ proteins • Information for making ___________ proteins is stored in the sequence of ____________________ nitrogen bases – __________________ A= Adenine – __________________ C=Cytosine – __________________ G=Guanine – __________________ T=Thymine Section 1: Why do cells divide? • In order to maintain this information, each human cell must be able to replicate its ____ DNA – Then divide the _____ DNA equally into __ 2 ________ daughter cells – In _________, eukaryotes this process is called _______ Mitosis • _______ Mitosis occurs before the _________ cytoplasm of the cell splits in two • giving each “___________” daughter cell one copy of the original parent _____ DNA and half the ___________ cytoplasm of the parent cell Section 2: Structures of the Cell Genetic information is passed from one cell generation • ___________ to the next by ________________ chromosomes • Chromosomes are made up of ______ DNA chromosomes – Every cell has a specific _________ number of ______________ • Example: A fruit fly has ___ 8 chromosomes, humans have ___ 46 chromosomes, and carrot cells have ____ 18 chromosomes Section 2: Structures of the Cell visible in most cells except – Chromosomes are not _______ for during _____ ________ cell division • at the beginning of cellular division ______ DNA and _________ proteins condense into compact visible structures called ______________ chromosomes • Each chromosome contains ___ _________ 2 sister chromatids _______ which are __________ identical to one another – These are attached usually in the middle by a _____________ centromere Section 2: Structures of the Cell Chromatid Centromere Kinetochore Section 2: Structures of the Cell Structure Chromatin Picture Description genetic thread-like _________ nucleus material found in _________ coiled before division into ____________ chromosomes and uncoils after division is complete Section 2: Structures of the Cell Structure Centromere Picture Description 2 strands holds ___ _________ of chromatids together to ___________ form a chromosome Section 2: Structures of the Cell Structure Picture Chromatid or Description 2 identical -__ _________ halves of chromosome -as cell________, divides each new chromatid cell receives __1 ___________ DNA makes copy -form as _____ before division Section 2: Structures of the Cell Structure Picture Chromosome or Description = ________ genetic material (rod shaped structure made of _____ DNA and_________) proteins chromatids -2 paired ___________ - each human cell has ____ 46 Section 2: Structures of the Cell Structure Spindle Fibers Picture Description guide _________ genetic material around cell microtubules -Made of ______________ Section 2: Structures of the Cell Structure Metaphase Plate Picture Description ___________; middle of cell equator Section 2: Structures of the Cell Structure Poles Picture Description opposite ends of cell __________ -where ___________are centrioles located -location of genetic material _________ AFTER separation Section 2: Structures of the Cell Structure Clevage Furrow Picture Description where _________ animal cell pinches off to form ___ 2 new cells Animal Cytokinesis -___________________ Section 2: Structures of the Cell Structure Cell plate Picture Description where cell divides in plant cells _______ -_____________________ Plant cytokinesis Section 2: Structures of the Cell Structure Daughter cells Picture Description contains _________ _______ identical genetic information as the parent cell 46 chromosomes - contains ___ - known as ________ diploid Section 2: Structures of the Cell Structure Gametes Picture Description ________(male – sperm; sex cells female-egg) half the - cell contains _____ genetic material as _________ parent cell - _____ 23 chromosomes - known as ________ haploid Section 2: Structures of the Cell Structure Picture Description Histones DNA - made of ___________ proteins - only in __________ eukaryotic cells - help maintain shape of chromosome _____________ - aid in tight packing of _____ DNA Section 3: Cell Cycle cycle of cell growing and dividing • Cell Cycle: ________________________________ length varies depending on type of cell – ____________________________________________ 24 Hours – For most mammals= ____________ • 3 Stages Interphase – _____________________ Mitosis – _____________________ Cytokinesis – _____________________ Section 3: Cell Cycle • Interphase: time – Most of the_________ is spent here G1, S, and G2 – Includes: ___________________ cell grows to full size • G1 = ___________________________________________ DNA replicates, producing 2 sister chromatids • S=_____________________________________________ replication of organelles, chromatids coil • G2= ___________________________________________ to form chromosomes 46 chromosomes, and ends with ____ 46 in – Begins with ____ each cell Section 3: Cell Cycle Section 3: Cell Cycle replication of body cells • Mitosis= _________________________________ – Broken into 4 steps Prophase 1. ____________________ Metaphase 2. ____________________ Anaphase 3. ____________________ Telophase 4. ____________________ Section 3: Cell Cycle Drawing Phase Prophase Description What’s Happening: spindle fibers form nucleus breaks up Genetic Information: chromatin condenses and forms chromosomes -each half = sister chromatid Section 3: Cell Cycle Drawing Phase Metaphase Description What’s Happening: metaphase plate forms Shortest phase! Genetic Information: paired chromatids line up on equator (Metaphase plate) Section 3: Cell Cycle Drawing Phase Anaphase Description What’s Happening: centromere splits and guides a single chromatid to the poles along spindle fiber Genetic Information: single (sister) chromatid Section 3: Cell Cycle Drawing Phase Telophase Description What’s Happening: cleavage furrow forms - nucleus reappears - spindle fibers disappear Genetic Information: chromatids change back into chromatin Cytokinesis: division (pinching) of cytoplasm occurs Section 3: Cell Cycle Drawing The End: Phase Result: Daughter Cells Description What’s Happening: each cell is identical to each other Genetic Information: diploid (46 chromosomes each) Storm Tracker (5.1)…. How long do you suppose it takes for the following cells to “regenerate” by going through the division process? 24 hours – Skin cells = _______________ 3-5 days – Taste bud cells = ______________ never – Cardiac Cells = _______________ Over a year – Liver cells = _______________ Never – Nerve Cells = _______________ What happens when cell division becomes out of control (and won’t stop?) cancer Section 3: Cancer Cancer ____________ • defined as the continuous uncontrolled growth of __________ cells proliferation or tumor – A __________ is a any abnormal ______________ rapid increase in number of cells. benign • __________ tumors stays confined to its original ___________ location • ____________ Malignant tumors are capable of invading surrounding __________ tissues or invading the entire ________ body cell type – Tumors are classified as to their __________ • Tumors can arise from any cell type in the body Section 3: Cancer • Causes of Cancer: – __________________________ genetic predisposition – __________________________ environmental influences • __________________________ infectious agents • __________________________ ageing normal cells into cancerous -These transform ________ ones by derailing a wide spectrum of ______________ pathways to promote and prevent regulation over populating a given area Section 3: Cancer • _____________ cell cycle control system •regulated by both ____________ internal and ___________ external controls •has specific ______________ checkpoints where the cell cycle stops until a go-ahead___________is received signals G1 checkpoint M checkpoint G2 checkpoint Section 3: Cancer G1 checkpoint is the most •For many cells, the ________________ important •If a cell receives a go-ahead signal at the G1 S _____, G2 checkpoint, it will usually complete the ___, _____ M phases and divide not receive the go-ahead signal, •If the cell does _____ it will exit the cycle, switching into a G0 phase nondividing ____________ state called the _______________ Storm Tracker (5.2) Answer the questions below. 1. What evidence in your own life do you have that cell division is regulated by your body? »Left »A ear is about same size as right ear. cut on your finger heals, but the skin doesn't just keep growing! Section 3: Cancer internal signals •Examples of _________ –Errors in _________ S-phase •molecular _________ sent that prevents cell signal from leaving ____ G2 Kinetochore does not attach to –______________ ______________: molecular signal sent that spindle fiber delays _____________ anaphase Section 3: Cancer external Signal - An Example of an ________ Growth –__________ factors Proteins released by certain cells that •__________ divide stimulate other cells to _________ Section 3: Cancer density dependent inhibition •________________________ –crowded cells stop _____________ dividing contact inhibition –Also known as ____________________ anchorage dependence •________________________ –Most cells must be attached to a foundation in order to ___________ divide Cancer Cells exhibit neither ______________ •______________ density dependent inhibition nor ____________ anchorage dependence Section 3: Cancer anchorage dependence density dependent inhibition density dependent inhibition normal cells cancer cells Section 3: Cancer • Cancer cells lack a ________________________ contact inhibitor – growth mechanism which functions to keep cells growing into a ______________ one cell layer thick (a______________). monolayer – If a cell has plenty of _______, space it replicates _________ rapidly and moves ________ freely – If a cell comes into contact with another then they will stop ___________ dividing Normal Cells Cancer Cells Section 3: Cancer • Cancerous cells continue _______ growing and _______ moving when they touch other cells. »They ______ pile up and ________ migrate to other parts of the body -- the __________ spreads. cancer • _________________ Growth Factors »made of ___________ protein »___________ chemical messages that control the cell cycle Section 3: Cancer • Growth Factors stimulate __________________ cellular division – these_________ through the body diffuse making contact with many different cells – Bind to _______________________, like membrane receptors a key fitting into a lock. • stimulate a pathway inside cell that leads to _____________________ cellular division – Each __________ binds to a different receptor _________________ growth factor – Different ______________ are stimulated cell types by different growth factors. Section 3: Cancer • Role of ______ growth factors in _______ normal cells growth factors growth factors _______________ binds to receptor ___________ receptors sets off a signal to the nucleus target cell enters ________ S-phase and __________, divides repairing wounds cancer cell Several ways to get faulty growth factors in a ________ 1. cell might produce its own ________________ growth factor mutant receptor might turn 2. ________________ on even without binding to growth factor signals may occur 3. _________ even without trigger from receptor 4. in each case, cancer cells enter ___________ and S-phase divide causing a __________ tumor Section 3: Cancer • Cancer in our _______ Genes – ___________________: Proto-oncogenes: • Genes that code for _________________ Growth Factors • Active in actively dividing ___________ tissues (example: ________) skin • Sometimes mutate into...... – ____________: Oncogenes: • genes that cause __________ cancer • produce too much ______________ Growth Factors – Over stimulate ___________ mitosis Section 3: Cancer • ________ Tumor Suppressor Genes – Code for ___________ that turn off cell proteins division • example: ___________ p53 gene – p53 Gene • Codes for a ________ protein that stops the cell cycle after ____ G1 • Half of all cancers involve ___________ p53 gene Section 3: Cancer 3 • ____ major types of cancer: 90% of 1. _______________constitute ______ Carcinomas cancers, are cancers of _____________ cells epithelial • Epithelial Cells: composed of one or more cells layers of densely packed _______ In vertebrates, it lines the outer layer of the _________, the surface of skin most_______________, and the lumen of body cavities fluid-filled ________, such as the gut or organs intestine Section 3: Cancer Sarcomas 2. ___________are rare and consist of tumors _________ of _____________________ connective tissues • Connective tissues=________________ bones, muscles ___________________________________ Leukemias 3. ___________ and ____________-constitute lymphomas 8% _____ of tumors. Sometimes referred to as liquid tumors. Leukemia's arise from blood forming cells and lymphomas arise _______ immune system from cells of the ________________ Section 3: Cancer Density Dependence Inhibition: most normal animal cells in culture that stop dividing once they come into direct contact with another cell Anchorage Dependence: need for contact and anchorage to a stable surface by some cells in order to grow, function, and divide Proto-oncogenes:a gene involved in the signalling or regulation of cell growth Growth Factor: a complex family of proteins that are produced by the body to control growth, division and maturation of cells
