Pharmacology researcher, hope I helped :)
Not all bacteria is harmful to your health.
There are a few bacteria that are helpful and harmless, such as lactoballius.
A teratogen is any substance or agent that interferes with the normal development of a fetus in the womb. Examples include drugs (prescription and nonprescription), pollutants, maternal malnutrition, infectious diseases, etc.
Factors that influence a teratogen: The dose or amount of the substance to which the fetus is exposed, the length of time that the fetus is exposed, and the genetic vulnerability of the individual fetus.
For 80–90% of people who have total knee replacement, the new joint should last about 20 years, and it may well last longer. If you've had a partial knee replacement, you're more likely to need a repeat operation – about 1 person in 10 needs further surgery after 10 years. The main reason people have this type of surgery is to no longer suffer from chronic and excruciating pain.
I only know it's a process of change of matter but I don't remember the exact types
