binary fission: cell division in prokaryotic cells asexual reproduction in which one cell divides...
TRANSCRIPT
Binary Fission:• Cell Division in Prokaryotic Cells• asexual reproduction in which one cell divides
into two identical daughter cells
The Cell Cycle
How cells divide to make new cells
Just like people have phases of development,
Cells have phases too.
In somatic (body) cells, a parent cell
produces 2 daughter cells.
The purpose of cell division is for growth and repair
of tissue.
Three Phases or Stages
1. Interphase2. Mitosis3. Cytokinesis
Interphase
Interphase DNA and organelles replicate Cell spends most of its life in
this stage
Stages of InterphaseG1 (growth) normal activities – endo & exo
S (synthesis) genetic material is duplicated so each daughter cell contains the same amount of genetic material as the parent cell
G2 (growth) preparing for cell division
Mitosis
Nucleus divides Duplicated DNA is divided
into two new nuclei
Stages of Mitosis
ProphaseMetaphaseAnaphaseTelophase
Prophase
Prophase
• Nuclear membrane breaks down• Genetic material (chromatin)
condenses• Centrioles migrate to opposite
ends of poles (in animal cells)•Microtubules (spindle fibers)
attach to centrioles
Prophase
Metaphase
Metaphase
• Duplicated chromosomes line up on the equator of the cell
• Microtubules (spindle fibers) attach to centromere at kinetochore
Metaphase
Anaphase
Anaphase
• Duplicated chromosomes (also called sister chromotids) separate
• 1 of each pair are pulled apart toward opposite poles of the cell
Anaphase
Telophase
Telophase
• New nuclear membranes form to separate the genetic material
• Cleavage furrow in animal cells
• Cell plate in plant cells
Telophase
Mitosis
Cytokinesis
Cytokinesis
• Occurs AFTER telophase and BEFORE interphase
• Cytoplasm divides
Cytokinesis
What happens when cells divide at an uncontrollable rate?
CANCER
Causes of Cancer
• Tobacco•Radiation exposure•Viral infections (HPV)•Genetics
