Scratch

im am making a game where you click a dot and a plant grows. The dot represents Sunlight and you have to gather the sunlight for the plants, until they grow a flower at the top. At the moment when you click the dot the dot moves to a random place and moves in a random direction. One segement of plant is visible from the star and i want to click the dot and have the other plants change their costumes from the white square to the plant segement, one by one, so each click the next segement becomes part of the plant until they reach the top of the plant and a flower appears at the top. How will i program these segements and the flower to appear?

Thanks to anyone who tries to help.