Final answer:
It is not specified how much radiation radish seeds could endure and still sprout. Simpler organisms can tolerate significantly higher levels of radiation than humans; therefore, humans would not survive the doses used in food irradiation.
Step-by-step explanation:
The maximum amount of radiation that radish seeds could tolerate and still germinate is not provided in the context. However, we do know that different organisms have varying levels of radiation tolerance. Generally, simpler organisms can withstand higher doses of radiation compared to more complex ones like humans. For instance, in food irradiation, licensing allows up to 1000 Gray (Gy) for fresh fruits and vegetables, which is considered a low dose, but this amount is already enough to be lethal to humans. Microorganisms require about 10,000 Gy to be destroyed, and fungi even more. Thus, compared to radish seeds, humans would not be able to survive the amounts of radiation that are used for food irradiation and sterilization.