Cell Division - Mitosis Flashcards
Where does the cell cycle start and end?
Mitosis
What happens in gap phase 1?
Cell grows and new organelles and proteins are made
What happens in the synthesis stage?
Cell replicates it’s DNA, ready to divide by mitosis.
What happens in gap phase 2?
Cell keeps growing and proteins needed for cell division are made.
Which stages of the cell cycle are in interphase?
Gap Phase 1
Synthesis
Gap Phase 2
What happens during interphase?
Cell prepares to divide
Cell’s DNA unravelled and replicated to double genetic content
Organelles also replicated
ATP content increased
What is produced via mitosis?
2 genetically identical daughter cells
What is mitosis needed for?
Growth and repair
What are the separate strands called in a chromosome?
Chromatids
What joins these chromatids?
Centromere
What are the 2 strands on the same chromosome called?
Sister chromatids
What is the first stage of mitosis?
Prophase - chromosomes condense, centrioles move to opposite ends of cell forming the spindle, nuclear envelope breaks down, chromosomes free in cytoplasm
What is the second stage in mitosis?
Metaphase - chromosomes line up in the middle of the cell and attach to spindle by centromere
What is the third stage of mitosis?
Anaphase - centromeres divide, sister chromatids separate, pulls chromatids to opposite poles of spindle, chromatids appear v-shaped
What is the fourth stage of mitosis?
Telophase - chromatids reach opposite poles on spindle, chromosomes again, nuclear envelope reforms, cytokinesis, 2 daughter cells
Which areas of the cell cycle do cancer treatments target?
G1 (cell growth and protein production)
s phase (DNA replication)
How do you prepare a root tip cell squash?
- Add 1 M HCl to boiling tube. Enough to cover root tip. Put tube in water bath at 60 °C
- Cut 1cm from tip of root (where mitosis takes place)
- Transfer root to boiling tube and incubate for 5 mins.
- Remove root and rinse. Leave tip to dry.
- Place on slide, cut 2mm from tip.
- Break tip open and spread cells out thinly.
- Add stain
- Cover slip and squash.
- Look under microscope
How do you use an optical microscope?
- Clip slide to stage.
- Choose lowest powered objective lens.
- Use coarse adjustment knob to bring stage below lens.
- Look down eye piece. Use CAK to move stage down until in focus.
- Adjust with FAK
- Swap to higher powered objective lens.
How do you calculate mitotic index?
Number or cells with visible chromosomes/ total number of cells observed
How do you calculate the actual size of cells?
- Line up eyepiece graticule with stage micrometer
- Work out the value of divisions on the eyepiece graticule at a particular magnification.
- Take stage micrometer away and replace with slide to measure size of cells.