Cell division is responsible for
- growth - increases size
- repair - repair damaged cells
- reproduction - two identical cells
Skin cells or Somatic cells undergo
cells make up skin
cells that reproduce by cell division
the process that divides the nuclear material during cell division
DNA (deoxyribonuleic acid)
a long molecule that provides instructions for making, running, and repairing a cell
RNA (ribonucleic acid)
one strand of DNA
Why is DNA important?
DNA is the GENETIC CODE that is a unque pattern of base pairings to for characteristics.
Structure of DNA
- twisted ladder, nucleotides, nitrogenous base molecule
- sides: sugar and phosphate
Base Pairings: (nitrogenous bases)
Adenine & Thymine, Guanine & Cytosine
Cell Cycle- the sequence of events in the cell from one cell division to another
- Telophase, Cytokensis
growing and working, 90%
sister chromotids visible, join 'X' shape, nuclear membrane breaksdown chromosomes spread out
spindle formed, chromotids attach to spindle fibres, chromotids line up in centre
chromotids pulled apart from spindle goes toward opposite poles of cell, chromotids called chromosoes
- new chromosomes reach opposite poles
- events of prophase happen in reverse
- two nuclear membranes form
- spindle disappears
- chromosomes lengthen and get thinner
- nucleoli reappears
- divides cytoplasm in two daughter cells
- pinching of cell membrance and cytplasm
- between two new nuclei
a change in DNA (genetic code) of a cell
What does a mutation do?
A harmful mutation in a gene's DNA causes change in the protein that is produced.
What does a mutation affect?
The body's functions.
- benign - harmless
- malignant- harmful, spreads
What does a malignant tumor's cell look like?
The nuclei is enlarged, the cell is bigger.