Gen Bio

• It is the process by which a parent cell divides into two or more daughter cells.

  Cell Division
• Cell Division ensures the continuity of life and the growth and repair of tissues in living organisms
• All cells are derived from pre-existing cells
• New cells are produced for growth, to replace damaged old cells and for the production of sex cells
• Cell division differs in prokaryotes (bacteria) and eukaryotes (protists, fungi, plants, and animals)
• The instructions for making cell parts are encoded in the DNA
• Each new cell must get a complete set of the DNA molecules
• It is a molecule that carries the genetic instructions used in the growth development, functioning, and reproduction of all known living things. 


  DNA
• DNA or deoxyribonucleic acid
• Most eukaryotes have between 10 and 50 chromosomes in their body cells
• All eukaryotic cells store genetic information in chromosomes
• Human body cells have 46 chromosomes or 23 pairs of chromosomes
• It is a visual representation of the complete set of chromosomes in an organism's cell

  Karyotype
• It is the complex of DNA and proteins that makes up the genetic material in the nucleus of a eukaryotic cell during the interphase of the cell cycle

  Chromatin
• A single DNA strand in a replicated chromosome

  Chromatid
• Structure in the chromosome that holds together the two chromatids

  Centromere
• A chromosome is a condensed and visible structure formed by the coiling and folding of chromatin
• Asexual reproduction involves a single cell dividing to make 2 new, identical daughter cells
• Examples of asexual reproduction is Mitosis and Binary Fission
• Sexual reproduction involves two cells (egg & sperm) joining to make a new cell (zygote) that is not identical to the original cells
• example of sexual reproduction is meiosis
• "Putting it all together'

  Fertilization
• Prokaryotes such as bacteria divide into 2 identical cells by the process of binary fission
• In cell division of prokaryotes, single chromosome makes a copy of itself
• In cell division of prokaryotes, cell wall forms between the chromosomes dividing the cell
• A series of events that occur in a cell, leading to its division and the production of two daughter cells

  Cell cycle
• Are proteins that play a crucial role in regulating the progression of the cell cycle, particularly at key checkpoints

  Cyclins
• Cyclins work in conjunction with cyclin-dependent kinases (CDKs), forming complexes known as cyclin-CDK complexes
• Stages of Cell Cycle:

  1. G1
  2. S
  3. G2
  4. Mitosis
  5. Cytokinesis
• G1 stage


  Interphase
• 1st growth stage after cell division

  Interphase - G1 Stage
• Cells mature by making more cytoplasm and organelles


  Interphase - G1 Stage
• Cell carries on its normal metabolic activities

  Interphase - G1 Stage
• main decision point for the cell, primary point at which it must choose whether or not to divide

  G1 checkpoint
• At G1 a cell checks the cell size, nutrients, growth factors and DNA damage of a cell
• Synthesis stage


  Interphase - S Stage
• DNA is copied or replicated


  Interphase - S Stage
• 2nd Growth Stage


  Interphase - G2 Stage
• Cells continue to grow

  Interphase - G2 Stage
• Checks for DNA replication errors

  Interphase - G2 Stage