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Published byFernanda Bleckley Modified over 10 years ago
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AP LAB #3 part C Crossing Over during Meiosis in Sordaria… counting map units
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Sordaria fimicola is a type of FUNGUS, found in the group known as ASCOMYCOTA
“Sac fungi”
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Ascus are found in here… in the ascocarp!
The shared derived character that defines the Ascomycota is the ascus. It is within the ascus that nuclear fusion and meiosis take place. Ascus are found in here… in the ascocarp!
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Sordaria fimicola~ ASCOMYCOTA
See, here they are… ASCI!
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Sordaria fimicola~ ASCOMYCOTA
This is what it looks under a scanning e- microscope!
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Sordaria fimicola~ ASCOMYCOTA
Here they are… ASCI! ~ they hold ASCOSPORE
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Sordaria fimicola~ ASCOMYCOTA
Here they are… ASCI! ~ there are chromosomes inside those dots!!
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In the ascus, meiosis occurs, followed by a round of mitosis
In the ascus, meiosis occurs, followed by a round of mitosis. This leaves eight nuclei, and eventually eight ascospores THERE ARE CHROMOSOMES INSIDE THOSE SPORES… AND WITHIN THE CHROMATIN, THERE ARE GENES…. These genes code for traits… COLOR
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Ascospores are formed within the ascus by an enveloping membrane system, which packages each nucleus with its adjacent cytoplasm and provides the site for ascospore wall formation
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Sordaria fimicola~ ASCOMYCOTA
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Sordaria fimicola~ ASCOMYCOTA
Meiosis II Meiosis I S phase
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Sordaria fimicola~ ASCOMYCOTA
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Sordaria fimicola~ ASCOMYCOTA
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Sordaria fimicola~ ASCOMYCOTA
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Sordaria fimicola~ ASCOMYCOTA
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Sordaria fimicola~ ASCOMYCOTA
No X-over How many DID NOT crossover?
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Sordaria fimicola~ ASCOMYCOTA
Did X-over How many DID crossover?
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Sordaria fimicola~ ASCOMYCOTA
How many DID crossover? X 100 Total counted
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Sordaria fimicola~ ASCOMYCOTA
349 X 100 609
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Sordaria fimicola~ ASCOMYCOTA
. 573 X 100 = 57.3
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Sordaria fimicola~ ASCOMYCOTA
Divide this number by 2 How many DID crossover? X 100 Total counted
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Sordaria fimicola~ ASCOMYCOTA
. 573 X 100 = / 2
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Sordaria fimicola~ ASCOMYCOTA
=
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Sordaria fimicola~ ASCOMYCOTA
= this means MAP UNITS
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Sordaria is a haploid organism for the majority of its life cycle
It becomes diploid only when mycelia fuse and two different types of haploid nuclei form a diploid nucleus.
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