What are the steps toward multicellularity, in the correct order?

First a colony of protists forms, then some protists start to specialize in specific tasks, and finally some cells become gametes.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.