{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Exam Two Notes - Exam Two Notes Mitotic Segregation The...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Exam Two Notes 2/18/08 Mitotic Segregation The purpose of mitosis is to produce two genetically identical nuclei.  Is mitosis the same as cell  division?  No. Cell Division = (Mitosis + Cytokinesis) Cytokinesis: Cleaves the cytoplasm Many mitotic events occurring without the subsequent cytokinetic events produces a multi- nucleic tissue.  (spelling? Synciatium) Found in muscle. In insect development, synciatiual is multi-nucleic tissue. Mitotic Segregation: In mitosis, homologous chromosomes do not pair. Mitotic Segregation can occur in two major ways. 1) Mitotic non-disjunction: In non-disjunction, the centromere does not separate  correctly. 2) Crossover: This is rare, because homologous chromosomes do not pair in  mitosis.  They have to lie just opposed to crossover (Mitotic crossing over). This can produce variegation.  The coexistence produces different-looking sectors of somatic  tissue. Somatic tissue in the animals is the tissue that does not contribute genetically to the gametes.  In plants, since differentiation of tissues can occur, tissue that was somatic may lead to germ  line tissue (does contribute genetically).  Somatic tissue differentiates into germ line tissue. Can have an environmental cause. Slide 40: Single yellow spot versus twin spot. mosaic is an individual composed of tissues of two or more genotypes.
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Variegation is a way of being mosaic. In the 1930’s, Calvin Bridges discovered some +/M Drosophila females that were variegated  because mitotic nondisjunction had produced mosaics containing sectors of two different  genotypes.  Here M causes slender bristles and it is dominant to the wildtype +. He discovered mitotic nondisjunction in Drosophila. In 1936, Curt Stern found the first case of mitotic crossing-over. y= yellow body … sn = singed bristles y+ sn/y +sn X y sn /Y Female progeny, heterozygous wild type. Slide 48.  Explain the production of a single yellow spot and a twin spot. 2/22/08 The Poisson distribution A distribution is the description of the proportions of the different types of classes that result  from sampling. The Poisson distribution describes the proportion of classes containing 0, 1, 2, 3, etc. items  when the average number of items per sample is known. The distribution is most suited to situations in which the average is small in relation to the total  number of items possible.  Eg: The number of holes in a leaf made by a certain species of  insect.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern