In prokaryotic cells, there is only one point of origin, replication occurs in two opposing directions at the same time, and takes place in the cell cytoplasm. Eukaryotic cells on the other hand, have multiple points of origin, and use unidirectional replication within the nucleus of the cell.
Answer:
A producer. For example in a common food chain, grass->grasshopper->mouse->snake->eagle. The grasshopper eats grass which is a producer so if there aren't anymore insects like grasshoppers, then the grass grows more.
Thyriod gland is the right answer