Cells Arise From Other Cells Flashcards
What is the mitotic index?
The percentage of cells undergoing mitosis or the ratio between the number of cells and the number of cells in interphase
What is step 1 in calculating mitotic index?
Count the number of cells undergoing mitosis (prophase, metaphase, anaphase and telophase)
What is step 2 in calculating mitotic index?
Count the total number of cells in the field of view
What is step 3 in calculating mitotic index?
Use the formula: Mitotic index in % = number of cells undergoing mitosis / total number of cells viewed x 100
What is the mitotic index formula?
Mitotic index in % = number of cells undergoing mitosis / total number of cells viewed x 100
What is the order for mitosis?
Interphase, Prophase, Metaphase, Anaphase, Telophase
What happens in Interphase?
- DNA replicates- Organelles replicate- DNA is folded up in chromatin- Cannot see chromosomes
What happens in Prophase?
- Nuclear envelope breaks down- Chromosomes condense- Centrioles move to the poles
What happens in Metaphase?
- Double chromosomes line up on the equator- Spindle forms- Spindle attaches to centromeres
What happens in Anaphase?
- Centromeres split- Chromatids are pulled to opposite poles
What happens in Telophase?
- Nuclear membrane reforms- Cytokinesis- Two genetically identical cells are formed
What is cytokinesis?
The division of the cytoplasm
What is mitosis?
Cell division to form 2 genetically identical daughter cells
Why does mitosis happen?
- For growth and repair
How many cells are formed as a result of mitosis?
2 daughter cells from 1 division
How many stages are there in mitosis?
4
What are the 4 stages of mitosis?
Prophase, Metaphase, Anaphase, Telophase
What is cancer?
Uncontrolled cell division
How can cancer occur?
When one of the genes that controls mitosis mutates causing rapid uncontrolled division often forming a tumor
What happens during cancer treatment?
Cancer treatment controls cell division by killing both normal and cancerous cells but because cancer cells divide more often more cancer cells are killed than normal cells
What is binary fission?
Asexual reproduction of single celled organisms e.g. bacteria
How does binary fission happen?
The circular loop of DNA replicates and moves to opposite ends of the cell, the plasmids then replicate and the cytoplasm splits to form two daughter cells each with a single copy of the circular loop of DNA.
