LAB 7 MITOSISMEIOSIS Slide show by Kelly RiedellBrookings

LAB 7 MITOSIS/MEIOSIS Slide show by Kelly Riedell/Brookings Biology http: //www. tokyo-med. ac. jp/genet/anm/mimov. gif

http: //www. vcbio. science. ru. nl/en/image-gallery/show/PL 0096/labels/

http: //district. bluegrass. kctcs. edu/rmccane 0001/shared_files/bio 137 website/BIO 137/137 Lab 2/Lab 2 Mitosis. Slides. html

Sordaria Life Cycle http: //botit. botany. wisc. edu/toms_fungi/mar 2007. html

Sample of Sordaria in petri dish

Sample of all black spores • To the right is a photo of asci that resulted from a cross between two black strains that is both parental strains had black colored spores • All of the 8 asci spores are black

Sample of tan spores • To the right is a photo of asci that resulted from a cross between two tan parental strains. • All of the 8 asci spores are tan.

Black and tan cross • To the right is a photo of asci that resulted from a cross between black and tan strains. • Some asci have 4 black spores and then 4 tan (4: 4) • Some asci display a 2: 4: 2 or 2: 2: 2: 2 sequence

http: //botit. botany. wisc. edu/toms_fungi/images/sordaria 2. jpg

Pattern WITHOUT crossing over

No Recombination Asci 4: 4

Pattern with crossing over

Recombinant Asci (Crossing over has occurred) 2: 2: 2: 2 or 2: 4: 2

Sample Problem

the number ascihave that have notover crossed Count the number of asciofthat crossed Youlooking are looking for 4: 4 orcombination You are for 2: 2: 2: 2 2: 4: 2 combination. 7 asci display crossing over 4 asci display crossing over 11 total asci

# of crossover asci TOTAL # of asci = % Asci showing Crossover ÷ 2 = Gene to centromere distance (map units)

http: //histoiresnaturelles. net/vegetaux/microscopie/sordaria_bouquet. JPG

DRAW THE EVENTS LEADING UP TO A 2: 4: 2 ascospore pattern (HINT: Work backwards from the final spore pattern) MEIOSIS II MITOSIS