3.2 Cell Division and methods of studying cells Flashcards
What are the 5 key stages of mitosis ?
Interphase, Prophase, Metaphase, Anaphase and Telophase
What are the products of mitosis ?
Two genetically identical daughter cells
What happens during prophase ?
- Nucleur membrane breaks down
- Chromatin condenses into chromosomes and become visible
- Centrioles move to opposite poles of the cell and spindle fibres become visible .
What are centrioles ?
Where the spindle fibres are released from and they are usually at each end of the cell
What happens during metaphase ?
- Chromosomes align along the centre of the cell
- Spindle fibres released attach to the centromere and chromatids
What is a centromere ?
A circular spot in the middle of two chromatids that holds them together
What happens during anaphase ?
- Spindle fibres retract and pull centromeres and chromatids that they are bound to to opposite sides/poles of the cell
What happens during telophase ?
- Chromosomes become longer and thinner so are not visible
- Spindle fibres disintegrate
- Nucleus starts to reform
What happens during cytokinesis ?
- The cytoplasm divides into two
- Two genetically identical daughter cells are formed
What happens during interphase (overview) ?
DNA is replicated and organelles are doubled
How do you calculate mitotic index ?
Number of cells in mitosis/ Total number of cells X100
What are the 3 main types of microscopes ?
- Optical
- TEM
- SEM
Define magnification
How many times larger the image is compared to the object
Define resolution
The minimum distance between two objects in which they can still be viewed as separate
How do you calculate magnification ?
Image size / Actual size
