{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Week 3, Lecture 2, Mitosis

Week 3, Lecture 2, Mitosis - Cell Cycle and Mitosis BIOLOGY...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 B I O L O G Y 0 2 3 19-Sep-09 Gardiner 1 Cell Cycle and Mitosis B I O L O G Y 0 2 3 19-Sep-09 Gardiner 2 Why do cells divide? Genetically Programmed Surface to Volume Ratio External Stimulus B I O L O G Y 0 2 3 19-Sep-09 Gardiner 3 Mitosis Mitosis – the equal division of one nucleus into two genetically identical nuclei Mitosis has to do with nuclear division not cell division B I O L O G Y 0 2 3 19-Sep-09 Gardiner 4 M (mitosis) Chromosomes have two chromatids Chromosomes condense (prophase) Chromosomes align at middle of cell (metaphase) Chromatids separate (anaphase) -amount of DNA in chromosomes ½ -ploidy number remains the same Cell divides (telophase, cytokinesis) B I O L O G Y 0 2 3 19-Sep-09 Gardiner 5 Ploidy The number of complete chromosome sets in a nucleus Diploid organisms ( 2n ) are those with two sets –i.e. humans, animals and many plants. Haploid organisms / cells ( n ) have only one set of chromosomes. Polyploid organisms have more than 2 sets of chromosomes B I O L O G Y 0 2 3 19-Sep-09 Gardiner 6
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
2 B I O L O G Y 0 2 3 Each chromosome is two chromatids per chromosome Each chromatid is a DNA double helix B I O L O G Y 0 2 3 Each human body cell has 46 or 23 pairs of these chromosomes during late prophase and metaphase B I O L O G Y 0 2 3 19-Sep-09 Gardiner 9 Cell division in Eukaryotic cells has two components Mitosis = division of the nucleus Cytokinesis = division of the cytoplasm Fig. 9.4 B I O L O G Y 0 2 3 Interphase B I O L O G Y 0 2 3 19-Sep-09 Gardiner 12 Interphase Occurs before stages of mitosis Genetic material is called Chromatin DNA replication occurs during this phase
Image of page 2
3 Interphase •Nucleus well defined •Nucleoli present •Centrosomes replicated (replicated centrioles in animal cells only) •Microtubules extend from centrosomes (called aster [star]) •Chromosomes have duplicated but not condensed Fig. 9.6 B I O L O G Y 0 2 3
Image of page 3

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

View Full Document Right Arrow Icon
Image of page 4
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