why do you have to sterilize seeds because i didn’t have to sterilize my spinach seeds?

Question: why do you have to sterilize seeds because i didn't have to sterilize my spinach seeds?
- Keywords:
  experiment,
  seed,
  sterilize
Asked by anon-218092 to Shannah on 13 Jun 2019.
- Shannah Gates answered on 13 Jun 2019:
  
  Because I grow my plants in sterile jars in the lab so if I dont sterilise them the bacteria and fungus will grow. I need the plants to be sterile so that when I add them to my liver cells I know that they are clean and that they wont infect my liver with bacteria or fungus.

Question: why do you have to sterilize seeds because i didn't have to sterilize my spinach seeds?