Question

there would be no plant life if chloroplast didno justifyt exist

Answer 1

This is because plants do photosynthesis with chloroplast.
Photosynthesis is the the process in which plants make their own food with the help of chloroplast, sunlight and water.
When there will be no photosynthesis then plants's survival will be affected for sure.

Answer 2

If chlorophyll didn't exist then the photosynthesis process will not take place because of which oxygen will not be produced.
Since not no life is possible without oxygen,therefore life will not exist on this earth.