The thompson family has four children , three girls and one boy. what caused this change to occur

The change where they didn't only have boys anymore but had a boy which was born was more likely due to the fact that there is generally a 50:50% chance of whether a boy or a giril will be born for any given family. 

They include lobsters and crabs

This is what i found on google “phytoplankton, tiny organisms that live in the ocean, are autotrophs. some types of bacteria are autotrophs. most autotrophs use a process called photosynthesis to make their food.” i hope this you for what your looking for