Slide 1
ANNOUNCEMENTSNo class next week fall breakMake sure to look at
your class grade on SakaiIf you have C- or lower in the class,
receive academic alertI highly suggest these students come see
meMust get C- or better in this classDeadline to withdraw Oct. 31st
Briefly discuss testput all materials away firstCell Division
Two Modes of Cellular ReproductionMitosis and MeiosisGerm Cells
Vs. Somatic CellsIn humans, the body cells (somatic cells)
reproduce by mitosis.
The germ cells in humans give rise to the gametes through
meiosis. Two Modes of ReproductionMitosis and MeiosisAsexual
reproduction (mitosis)
One cell makes an exact copy of itself. In eukaryotic organisms,
this is accomplished through mode of cell division called
mitosis.
Chromosome
Locus the position on a chromosome where a gene resides
Cell Cycle
Interphase vs. Mphase (mitosis or meiosis)
CytokinesisSee picture in lab manualMITOSISOnion Root Tip
Root CapZone of Cell DivisionZone of Cell Elongation
Onion Root TipYou also may want to watch the video link below on
the bead simulation of mitosis.
http://www.youtube.com/watch?v=zGVBAHAsjJMP 75 bead activity5-2
onion root tip5-3 whitefish blastulaThese correspond to questions
5-1 to 5-4 in the lab exerciseWhen complete we will move onto
meiosis Diploid vs. HaploidDiploid cells contain two sets of
chromosomes. One set inherited from each parent.Haploid cells
contain one set of chromosomes.
Two Modes of ReproductionMeiosisSexual reproduction (In Animals)
Each parent contributes chromosomes.Number of chromosomes stay
constant from generation to generation because the number of
chromosomes in the gamete is one half that of the parent cell.In
humans, gametes are formed through the process of meiosis.In
meiosis, four new cells are produced and the number of chromosomes
in each cell is cut in half.
Two Modes of ReproductionMitosis and MeiosisSexual reproduction
(In Animals) Two organisms produce cells called gametes (egg and
sperm)Gametes fuse during fertilization
Fig. 13-5KeyHaploid (n)Diploid (2n)Haploid gametes (n = 23)Egg
(n)Sperm (n)MEIOSISFERTILIZATIONOvaryTestisDiploidzygote(2n =
46)Mitosis anddevelopmentMulticellular diploidadults (2n =
46)21
Fig. 13-6KeyHaploid (n)Diploid
(2n)nnGametesnnnMitosisMEIOSISFERTILIZATIONMEIOSIS2n2nZygote2nMitosisDiploidmulticellularorganism(a)
AnimalsSporesDiploidmulticellularorganism(sporophyte)(b) Plants and
some
algae2nMitosisGametesMitosisnnnZygoteFERTILIZATIONnnnMitosisZygote(c)
Most fungi and some
protistsMEIOSISFERTILIZATION2nGametesnnMitosisHaploid
multi-cellular organism(gametophyte)Haploid unicellular
ormulticellular organism22
Fig. 13-4KeyMaternal set ofchromosomes (n = 3)Paternal set
ofchromosomes (n = 3)2n = 6CentromereTwo sister chromatidsof one
replicatedchromosomeTwo nonsisterchromatids ina homologous pairPair
of homologouschromosomes(one from each set)23
Fig. 13-7-1InterphaseHomologous pair of chromosomesin diploid
parent cellChromosomesreplicateHomologous pair of replicated
chromosomesSisterchromatidsDiploid cell withreplicated
chromosomes27
Fig. 13-7-2InterphaseHomologous pair of chromosomesin diploid
parent cellChromosomesreplicateHomologous pair of replicated
chromosomesSisterchromatidsDiploid cell withreplicated
chromosomesMeiosis IHomologouschromosomesseparate 1Haploid cells
withreplicated chromosomes 28
Fig. 13-7-3InterphaseHomologous pair of chromosomesin diploid
parent cellChromosomesreplicateHomologous pair of replicated
chromosomesSisterchromatidsDiploid cell withreplicated
chromosomesMeiosis IHomologouschromosomesseparate 1Haploid cells
withreplicated chromosomes Meiosis II2Sister chromatidsseparate
Haploid cells with unreplicated chromosomes 29
Fig. 13-12-5Prophase Iof meiosisPair
ofhomologsNonsisterchromatidsheld togetherduring
synapsisChiasmaCentromereAnaphase IAnaphase
IIDaughtercellsRecombinant chromosomesTEM30
Fig. 13-11-3Possibility 1Possibility 2Two equally
probablearrangements ofchromosomes atmetaphase IMetaphase
IIDaughtercellsCombination 1Combination 2Combination 3Combination
431
Fig. 13-9aMITOSISMEIOSISMEIOSIS IProphase
IChiasmaChromosomereplicationHomologouschromosomepairChromosomereplication2n
= 6Parent cellProphaseReplicated chromosomeMetaphaseMetaphase
IAnaphase ITelophase IHaploid n = 3Daughter cells ofmeiosis
IMEIOSIS IIDaughter cells of meiosis IInnnn2n2nDaughter cellsof
mitosisAnaphaseTelophase32
Can be a haploid cell as well!
Interphase ProphaseMetaphase Anaphase
Mid-telophaseLate-telophase Daughter cellsP 78 meiosis bead
activity ends p.81Corresponds to 5-5 to 5-8 in lab exerciseDo 5-9,
using photos of meiosisAnswer 5-10info in lab manual and
powerpointOnion Root Tip Mitosis Stages
Interphase
Early Prophase
Middle Prophase Late Prophase
Metaphase
Anaphase Telophase & Cytokinesis