Why are the seeds scattered in the juicy pulp of tomato and arranged in a row in a pea pod?

Pea plant is leguminous developed from a single carpel. When the seeds mature, the fruit splits into the dorsal and ventral sides and discharges the seeds. The plants which are developed from a single carpel have their ovules attached to the ventral suture. Therefore the fruit is developed with marginal placentation and the seeds are arranged in a row. On the contrary, the tomato is a fleshy fruit developed from the superior or inferior ovary. The central chamber is divided into compartments because the margins of the carpels grow inward to the centre of the ovary. The ovules are attached by the placenta and are arranged radially on the axis. That is why the seeds are scattered.