Why are radishes, carrots, beetroots, and sweet potatoes thick, fleshy and bulging? Which part of the plant do they form?

Why are radishes, carrots, beetroots, and sweet potatoes thick, fleshy

1.	Why are radishes, carrots, beetroots, and sweet potatoes thick, fleshy and bulging? Which part of the plant do they form?
Answer» Why are radishes, carrots, beetroots, and sweet potatoes thick, fleshy and bulging? Which part of the plant do they form?