How could evolutionary changes in planes of cellular division produce different body forms?

Explanation: Through time, there was a general trend towards the evolution of more complex multicellular algal forms there with specialized cell and tissue types but no further elaboration of the diploid life cycle stage.

For example

priming, subsequent diversification of indeterminate branched forms with leaves and roots.

The relative dominance of each phase shifted from the gametophyte (as in bryophytes) to the sporophyte (as in vascular plants) during evolution.

Most tissues of the body grow by increasing their cell number, but this growth is highly regulated to maintain a balance between different tissues.