Answer/Explanation:
Onions are stem modifications of bulbs. Onions grow during a cold weather, but forms bulbs when the weather is warm. Onions can either be grown using seeds or through their bulbs. That is why, the stem modification of onions are bulbs. Tuber is from potatoes, whereas corm is from crocuses and gladioli.
Firstly, we need to know what a healthy ecosystem is. When an ecosystem is healthy, this would mean that it could supply all the resources that all organisms present in it and with all the resources, there is diversity. Old growth forests are considered healthy because of this reason. These forests remain untouched and had remained in providing the resources needed for the organisms present in it.
Urban sprawl..............
