The plants might die out because there is no one to pollinate them
Just say we have a big amount of tryptophan in the sense that it exceeds, tryptophan would act as a co-repressor which prevents synthesis of more enzymes for its production
Hope this helps :)
For number 1 the first arrow is the cell wall, the second is the membrane, and the last arrow would be the cytoplasm
For number 2 they are in distilled water Bc they are remaining the same and not shrinking up
For three draw the cells smaller salt water sucks the water out of them
For four they get smaller because the salt has a higher concentration making the water leave the cell. Once water has left the cell begins to shrink