Because continental crust undergoes heating and cooling cycles that lower it’s density , what do you expect to occur when oceanic and continental crust collide at a plate boundary ?

As continential plate has a lower density, when the oceanic plate and continetial plate collide the denses oceanic plate will be subducted under the less dense continential plate.

As mentioned in the question, although continential plate is thicker, the continental crust undergoes heating and cooling cycles that lower it’s density, while the oceanic plate was thinner but denser.

Therefore when they collide, the denser plate will slide under the less dense plate due to the convection current of magma.

While features like the ocean trench and volcanoes will be formed due to subduction and the accumulation of continential crust.

Hope it helps!

The answer would be plant growth.