Cell Division - Mitosis & Meiosis Lecture PowerPoint
CellDivisionMitosis &MeiosisImage: Cell Division, WikipediaFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Eukaryotic Cell CycleLike prokaryotic cell cycle, in that – Cell grows.– DNA is replicated.- Mitotic cell divisionproduces daughter cellidentical to the parent.– The timing of replicationand cell division is highlyregulated.Image: Cell cycle by Richard WheelerFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Eukaryotic Cell Cycle2 major phases: Interphase (3 stages)– DNA uncondensed Mitosis (4 stages cytokinesis)- Nuclear division & division ofcytoplasm– DNA condensedImage: Cell cycle by Richard WheelerFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
InterphaseNon-dividing stateWith 3 sub-stages:Gap 1 – cell grows in size– organelles replicatedSynthesis – replication of DNA– synthesis of proteinsassociated with DNAGap 2 – synthesis of proteinsassociated with mitosisImage: Cell cycle by Richard Wheeler; Interphase inOnion Cell Drawing & Photo, Source UnknownFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
MitosisDivision of somatic cells (non-reproductivecells) in eukaryotic organisms.A single cell divides into two identicaldaughter cells.Daughter cells have same # ofchromosomes as does parent cell.
Packing for the move When cell is not dividing DNA molecules in extended,uncondensed form chromatin Cell can only replicate andtranscribe DNA when in extendedstate.When cell is preparing fordivision DNA molecules condense toform chromosomes prior todivision.– each chromosome is a singlemolecule of DNA– easier to sort and organize thereplicated DNA into daughter cellsFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Mitosis4 sub-phases:1st – Prophase2nd – Metaphase3rd – Anaphase4th – Telophasefollowed byCytokinesisImage: Mitosis diagram, Marek KultysFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
1. Prophase3 Major Events- chromosomes condense- spindle fibers form(spindle fibers are specialized microtubulesradiating out from centrioles)- chromosomes are capturedby spindleImages: Prophase drawing, Henry Gray's Anatomy of the Human Body;Prophase Onion Cell Drawing & Photo, Source Unknown, Fluoresced cell,National Institutes of HealthFluoresced eukaryotic cell.Chromosomes in blue. Mitotic spindleapparatus in green.From the Virtual Cell Biology Classroom on ScienceProfOnline.com
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2. Metaphase chromosomes align alongequator of the cell, with onekinetochore facing each polecentrioleschromosomesspindle fibersKinetocores not pictured in this illustration.Images: Metaphase drawing, Henry Gray's Anatomy of the HumanBody; Metaphase Onion Cell Drawing & Photo, Source Unknown
3. Anaphase sister chromatids separate spindle fibers attached tokinetochores shorten andpull chromatids towards thepoles. free spindle fibers lengthenand push poles of cell apartImages: Anaphase drawing, Henry Gray's Anatomy of the HumanBody; Anaphase Onion Cell Drawing & Photo, Source UnknownFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
4. Telophase spindle fibers disintegrate nuclear envelopes form around bothgroups of chromosomes chromosomes revert to their extendedstate cytokinesis occurs, enclosing eachdaughter nucleus into a separate cellImages: Telophase drawing, Henry Gray's Anatomy of the HumanBody; Telophase Onion Cell Drawing & Photo, Source UnknownFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Cytokinesis – Plant vs. Animal Cell Plant cells undergocytokinesis by forming a cellplate between the twodaughter nuclei. Animal cells undergocytokinesis through theformation of a cleavagefurrow. A ring of microtubulescontract, pinching the cell inhalf.Images: Telophase drawing, Henry Gray's Anatomy of the Human Body;Ciliate dividing, TheAlphaWolf; Telophase Onion Cell Photo, Source UnknownFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Stages of MitosisREVIEW!Mitosis Animations1. Mitosis & Cytokinesis from McGraw-Hill2. Mitosis Interactive Animation from Cells AliveImage: Onion Cell Drawing & Photo, Source Unknown
Genetics TerminologySEXually reproducingeukaryotes, have 2 types of body cells Madeyoulook!1. somatic cells2. sex cells(a.k.a. gametes, germline)Image: Superficial human anatomy, Mikael Häggström&Rainer Zenz; Sperm & egg, WikipediaFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
What is cell division of gametes called?Meiosis- A single germ cell divides into four unique daughter cells.- Daughter cells have half the # of chromosomes as parentcell, so they considered haploid.Image: Overview of Meiosis,National Institutes of HealthFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Genetics Terminology: PloidyRefers to the number of sets ofchromosomes in cells. Haploid – one copy of each chromosome– designated as “n”, the number ofchromosomes in one “set”- gametes Diploid – two sets of chromosomes- two of each chromosome– designated as “2n”- somatic cellsDiploid organisms receive one of each type ofchromosome from female parent (maternal chromosomes)and one of each type of chromosome from maleparent (paternal chromosomes)From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Genetics Terminology: HomologuesChromosomes exist in homologous pairs indiploid (2n) cells.Exception: Sex chromosomes (X, Y).Other chromosomes, known as autosomes, theyhave homologues.From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Karyotype Q: Which, of the top twokaryotypes is replicated? Q: How many homologouspair in each karyotype? Q: How is the bottomkaryotype different fromthe top two?From the Virtual Cell Biology Classroom on ScienceProfOnline.comImage: Karyotype, National Human Genome Research Institute
Sexual Reproduction Fusion of two gametes toproduce a single zygote. Introduces greatergenetic variation, allowsgenetic recombination. With exception of selffertilizing organisms,zygote has gametes fromtwo different parents.Images: Peter, Lois & Stewie, The Family GuyPeter Lois StewieFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Sexual reproduction in humans At fertilization, 23 chromosomesare donated by each parent.(total 46 or 23 pairs). Gametes (sperm/ova):– Contain 22 autosomes and 1 sexchromosome.– Are haploid (haploid number“n” 23 in humans). Fertilization results in diploid zygote.– Diploid cell; 2n 46. (n 23 in humans) Q: Most cells in the body are produced through what type of celldivision? Only gametes are produced through meiosis.Image: Superficial human anatomy, MikaelHäggström& Rainer Zenz; Sperm & egg, WikipediaFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Meiosis - Sex Cell (Gamete) FormationIn meiosis, thereare 2 divisionsof the nucleus:meiosis I&meiosis IIImage: Overview of Meiosis,National Institutes of HealthFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
REVIEW!Meiosis Animations2.1. How Meiosis Works from McGraw-HillMeiosis Interactive Animation from Cells AliveFrom the Virtual Cell Biology Classroom on ScienceProfOnline.comImage: Meiosis diagram, Marek Kultys
Meiosis & Sexual ReproductionLife CycleMitosis *From the Virtual Cell Biology Classroom on ScienceProfOnline.com**Image: Animal Life Cycle, Dr. T’s Bio 328 Genetics
Genetic Variation in Diploid Organisms Fusion of sperm and egg results inunique offspring. But not only because the young are aproduct of two individuals withdifferent genetic makeup. Meiosis “shuffles” the genes so thatthe an individual’s gametes aregenetically different from oneanother.How is this shuffling accomplished?From the Virtual Cell Biology Classroom on ScienceProfOnline.comImage: Meiosis diagram, Marek Kultys
Genetic shuffling of Meiosis IIn addition to a new combination of chromosomes resultingfrom fertilization, there are also events in Meiosis I thatshuffle the genes.1. Crossing overin Prophase I.2. Independent assortmentin Metaphase I.From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Crossing Over Homologues break atidentical locations, thenrejoin opposite partners. This creates newcombinations of the alleleson each chromosome. Occurs randomly severaltimes on every chromosome. Results in mixing of thegenes you inherited fromyour parents.From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Independent AssortmentREVIEW!Independent Assortment Animations2.1.Independent Assortment from Sinauer AssociatesRandom Orientation of Chromosomes During Meiosis from McGraw-Hill
Variation from geneticrecombination Independent assortment of chromosomes– meiosis introduces genetic variation– gametes of offspring do not have samecombination of genes as gametes from parents random assortment in humans produces223 (8,388,608) different combinations in gametesfrom Momfrom Dadoffspringnew gametesmade by offspring
Mitosis 2n Clone Same geneticinformation inparent cell anddaughter cell. Give me anotherone just like theother one!Meiosisvs. 1n Daughter cells different fromparent cell and from each other. Daughter cells have ½ thenumber of chromosomes assomatic cell. Shuffling the genes(Mix it up!) See animation “Unique Featuresof Meiosis” from McGraw-HillREVIEW!Animations Comparing Mitosis & MeiosisQuiz 1 and Quiz 2from McGraw-HillFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Image: Mitosis diagram & Meiosis diagram, Marek KultysFrom the Virtual Cell Biology Classroom on ScienceProfOnline.com
Drawing and Labeling catedUncondensedChromosome(chromatin)From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Drawing & Labeling Homologous m the Virtual Cell Biology Classroom on ScienceProfOnline.com
Confused?Here are links to fun resources that furtherexplain meiosis: Meiosis Main Page on the Virtual Cell Biology Classroom of “Meiosis: Where the Sex Starts”, video from Crash Meiosis animation, step-through and quiz, Sadava, et al., Life: The Meiosis step through animation from CellsAlive.com. Meiosis animation from McGraw-Hill. Independent Assortment animation from SinauerScience Prof Online.Course BiologyScience of Biology, 9th Edition, Sinauer Associates.Associates.From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Are you feeling blinded by science?Do yourself a favor. Use the Virtual Cell BiologyClassroom (VCBC) !The VCBC is full of resources to help you succeed,including: practice test questions review questionsstudy guides and learning objectivesPowerPoints on other topicsYou can access the Virtual Cell Biology Classroom (VCBC) on the Science Prof Onlinewebsite www.ScienceProfOnline.comImages: Blinded With Science album, Thomas Dolby; Endomembrane system, Mariana Ruiz, Wiki
Animal cells undergo cytokinesis through the formation of a cleavage furrow. A ring of microtubules contract, pinching the cell in half. From the Virtual Cell Biology Classroom on ScienceProfOnline.com . cell division lecture powerpoint, meiosis lecture, mitosis lecture, mitosis lecture ppt, meiosis lecture pptf, free cell division .
Now that you've seen how meiosis works, let's review two key differ-ences between the processes of meiosis and mitosis. Meiosis has two cell divisions. Mitosis has only one cell division. Meiosis results in haploid cells. Mitosis results in diploid cells. On the diagram above, circle the part in the process of meiosis
I II III IV A DNA Replication Mitosis Meiosis Fertilisation B DNA Replication Meiosis 1 Meiosis 2 Fertilisation C Fertilisation Meiosis Mitosis DNA Replication D Mitosis Meiosis 1 Meiosis 2 DNA Replication 4.4 In analysing the number of different bases in a DNA sample, the following result would be consistent with the base-pairing rules: .
During meiosis, a single cell goes through two cell divisions—meiosis I and meiosis II. Meiosis takes place only in the reproductive tissues of an organism. Cells divide twice during meiosis. Before meiosis begins, the chromosomes of the parent cell are copied. A cell that is ready to divide contains two copies of each
Cell Division in Sexual Reproduction: Meiosis Meiosis is the mechanism by which eukaryotic cells produce mature sex cells or gametes Meiosis produces four haploid cells (gametes) Meiosis involves partition of both cytoplasmic and nuclear structures Meiosis consists of Meiosis I and Meiosis II. Both phases are followed by .
Comparison of Meiosis II to Mitosis The events of meiosis II are like those of mitosis except in meiosis II, the nuclei contain the haploid number of chromosomes. At the end of telophase II of meiosis II, there are four haploid daughter cells that are not genetically identical. At the end of mitosis, there are two
Meiosis is a form of cell division that halves the number of chromosomes when forming specialized reproductive cells, such as gametes or spores. Meiosis involves two divisions of the nucleus—meiosis I and meiosis II. Before meiosis begins, the DNA in the original cell is replicated. Thus, meiosis starts with homologous chromosomes.
2. Mitosis begins and ends with genetically identical diploid2 cells, but Meiosis begins with a diploid germ cell and finishes with a haploid gamete cell. A very big difference! 3. There is only one set of PMAT cell division in Mitosis, but there are TWO sets of PMAT phases/two sets of cell division in Meiosis, and 4. There is no genetic .
Animal nutrition has pronounced direct impact not only on animal health but also indirectly through animal products on human health and through excreta on the environment. Due to increased awareness and concerns about animal health, due to increased incidence and severity of chronic non-communicable diseases in developed world that are linked to nutritional quality of (animal) food and due to .
