Goal 3 - The Cell Cycle and Mitosis
The Cell Cycle - How do cells reproduce?
(Reading pages 201-210)
What is cell division?
The Cell Cycle - Overview
S - Chromosomes are duplicated
G2 - Nuclear division phase – Mitosis. Process by which 2 daughters cells are formed, each containing a complete set of chromosomes.
Cell Cycle- Interphase
(Reading pages 201-210)
What is cell division?
- Process by which new cells are produced from one cell.
- Results are 2 cells that are identical to the original parent cell.
- To replace other cells that have been damaged or worn out
- To allow multicellular organisms to grow
- For asexual reproduction
- Because they get too big!
- Mitosis is the process in which one cell DIVIDES to make two new cells
- Each cell has the SAME genetic material as the original cell
- Its like “photocopying” the cell- They are IDENTICAL
- Genetic information is contained in the DNA of the cell
- DNA is found in long fibers called CHROMATIN
- Each long fiber makes up a CHROMSOME
- GENES are small sections of chromosomes that contain the information for a specific cell function
The Cell Cycle - Overview
- Stages between one cell division and the next.
- Cell cycle time varies from one cell to another.
- 2 general periods – growth and division
- Growth phase – Interphase.
S - Chromosomes are duplicated
G2 - Nuclear division phase – Mitosis. Process by which 2 daughters cells are formed, each containing a complete set of chromosomes.
- Cytoplasm divides separating into 2 daughter cells.
Cell Cycle- Interphase
- During INTERPHASE the cell is GROWING and preparing to reproduce, cell organelles are made - G1
- The cell’s DNA is being copied (replicated) - S
- The DNA is in the form of loosely coiled CHROMATIN
- Cell continues to grow and the replicated DNA is checked. If errors occur they are repaired. - G2
Mitosis
Cell Cycle- Mitosis
Mitosis is the stages of the cell cycle in which the cell DIVIDES
Mitosis is divided into:
Cell Cycle
The cell spends the most amount of time in INTERPHASE- growing
Mitosis- Early Prophase
Mitosis- Late Prophase
Mitosis- Metaphase
Mitosis- Anaphase
Mitosis- Telophase
Mitosis- Cytokenesis
Mitosis is the stages of the cell cycle in which the cell DIVIDES
Mitosis is divided into:
- Prophase - first
- Metaphase - middle
- Anaphase - apart
- Telophase – far or seperate
- Cytokenesis
Cell Cycle
The cell spends the most amount of time in INTERPHASE- growing
Mitosis- Early Prophase
- Chromosomes are condensed and consist of 2 sister chromatids
- The nuclear membrane begins to break down
- In animal cells ONLY, centrioles migrate to the opposite ends of cell.
Mitosis- Late Prophase
- Spindle fibers appear.
- The CENTROMERE joins each pair of sister chromatids to the spindle fiber.
Mitosis- Metaphase
- Chromosomes line up along the middle of the cell
Mitosis- Anaphase
- Spindle fibers separate sister chromatids and pull them apart
- Once they have separated they are individual chromosomes
Mitosis- Telophase
- Spindle fibers disassemble
- Nuclear envelope reforms
Mitosis- Cytokenesis
- In animal cells, new cell membranes form around each of the new cells
- In plant cells, new cell walls form on each side of the cell plate.
- The cytoplasm is divided between the two cells