2.6.1- Cell cycle

• 5 stages of the the cell cycle

  • G1 - growth
  • S- synthesis
  • G2 - growth
  • All of which are interphase
  • Mitosis - cell division
  • Some cells may enter G0 which prevents replication
• G0

  • Some cells don’t replicate as they could cause damage
  • Senescience- body prevents division
  • Apoptosis- controlled cell suicide
• G1

  • cell grows and increases in size
  • amount of mitochondria increases
  • proteins synthesis occurs so organelles duplicate
• S- synthesis

  • chromosomes are unwound and DNA is replicated
  • (2.3.2)
  • once the cell enters this stage it’s committed to completing the cycle
• G2

  • cell continues to grow
  • more cytoplasm and cell membranes are made
  • DNA is checked for errors
• CP1- between G1 and S- prevents uncontrolled cell division
• CP2- between S and G2- detects DNA damage- final chance to find mutation
• Silent mutation is an undetectable mutation
• Chromotides are connected by a centromere, singularly they are chromosomes
• Homologous chromosomes are the identical length and carry the same genes and alleles.