By preventing the synthesis of DNA halting cell growth.
Explanation:
Fluorouracil and methotraxate prevent the synthesis of the neucleoside Thymidine thus preventing DNA replication and elongation. Methotraxate has a structure analogous to Folic acid which is important for thymidine synthesis. Thus, it acts as a competitive inhibitor on dihdrofolate reductase an enzyme that is essential for tetrahydrofolate formation, a folic acid derivative.
Fluorouracil acts by inhibiting thymidylate synthase which catalyses an essential step in Thymidine synthesis.
Up to the the population carrying capacity the the population will increase to give a perfect balance and when the population will be much then the population will decrease.
