2What is Mitosis for? 1. Reproduction in favorable conditions. 2. Growth and Development3. Tissue repair and cell replacementIf an organism had the ability to reproduce sexually or asexually, which would they choose?
590% of cells are:___What if less than 90%?What is Cancer?
6What if a cell in G1 of interphase were fused with a cell in metaphase? G2 check- pointCyclinCdkMPF = ?
7MITOSIS: What phase is this cell most likely in? How many chromosomes? Would you see chromatin here?How many centromeres?How many sister chromatids?Draw this cell in Anaphase.How many kinetochores?How many spindle fibers will it take to move all of the chromosomes during metaphase and anaphase?What is the 2n number for this cell? What is the n number for this cell?
8Anaphase How many chromosomes? How many chromatids? What do the blue lines represent? What are they made of?The Kinetochores are very important here because…In which phase do spindle fibers start attaching to the kinetochores?In which specific phases (or parts of phases) will you find sister chromatids?Anaphase
9•What phase of mitosis?•Is this animal or plant?•What is this process called?• And in a plant, how is it different?Is this DNA in the chromosome or chromatin phase?
14Chromosome Number Homologous Chromosomes are the pairs Different # for different speciesFull set = 2n=Diploidn =full set= 46 in humans1 pair from mother, 231 pair from father, 23Humans= 23 pairs or46 total
15Autosomes & Sex Chromosomes Autosomes = # 1-22 for all traits except sexSex chromosomes =Pair # 23 XX(female) orXY(male) XXX? XXY? XYY? X?
16Meiotic Cells…….. 2n Divide twice to 1/2 chromosome number…WHY? ImmatureEgg orSperm still in the gonads2nDivide twice to1/2 chromosome number…WHY?“Haploid” nSperm or eggs only2n doubled DNA = X’sMeiosis I PMAT2n2nMeiosis II PMATnnnn
17How many differences can you come up with between meiosis and mitosis? 2 stages (PMAT,PMAT)4 daughter cells formedCrossing over (when?)Random assortment2 different metaphasesNot clonesHaploid (not diploid)MEIOSIS
18What is the longest phase of meiosis? why? What is synapsis? Chiasmata or chiasma? What is a tetrad?What is so important about what has happened here?
19Check out Metaphase I & II, what is different? What is the 2n number of this species?What is the n number?II
212n = ____ What might this cell look like in prophase I? in metaphase I of meiosis?in prophase II?What might each daughter cell look like after meiosis II?Is there a different daughter cell outcome that could have happened?What would each daughter cell look like after mitosis?2n = ____
22p.2302n n Alternate 2n & n animals fungi, algae plants, algae