G1/S checkpoint

G2/M checkpoint

M checkpoint

S/G2 checkpoint

$cd{K_4}/cyclinD$

$cd{K_6}/cyclinD$

Both (a) and (b)

$cd{K_2}/cyclinB$

The cell grows in size

DNA is replicated

Organelles are duplicated

Chromosomes condense and become visible

${\rm{M}}\, o \,{{\rm{G}}_{\rm{1}}}\, o \,{{\rm{G}}_{\rm{2}}}\, o \,{\rm{S}}$

$\,{{\rm{G}}_{\rm{1}}}\, o \,{{\rm{G}}_{\rm{2}}}\, o \,{\rm{S}} o {\rm{M}}\,$

${\rm{S}} o \,{{\rm{G}}_{\rm{1}}}\, o \,{{\rm{G}}_{\rm{2}}}\, o \,{\rm{M}}$

$\,{{\rm{G}}_{\rm{1}}}\, o \,{\rm{S}} o {{\rm{G}}_{\rm{2}}}\, o \,{\rm{M}}$

Interphase

Prophase

Metaphase

Anaphase

S-phase

${{\rm{G}}_1}$-phase

${{\rm{G}}_2}$-phase

Interphase

G1

G2

M

S

DNA replication

Growth and normal function of cell

Mutation

Fertilization

Interphase

Anaphase

Prophase

Telophase

${G_1}\,phase$

Synthesis phase

${G_2}\,phase$

M phase

${{\rm{G}}_1}$

${{\rm{G}}_2}$

${{\rm{G}}_0}$

M