It's the 4 the answer I hope it has served you
The fertilizers used by farmers can have negative effects on aquatic ecosystems because there is every possibility that the runoffs from the fields can create an algal bloom in the nearby water body. This algal bloom can have a very negative effect on the living organisms of the aquatic body. I hope it helps.
Insulin causes blood glucose levels to drop, which signals the pancreas to stop producing insulin in a negative feedback loop. Hormonal stimuli refer to the release of a hormone in response to another hormone. A number of endocrine glands release hormones when stimulated by hormones released by other endocrine organs.
Prokaryotes- lack a cell nucleus, unicellular, in the bacteria and archaea domain, lack mitochondria and chloroplast, microscopic
eukaryotes- contains a cell nucleus, multicellular, only in the eukarya domain, contains mitochondria and chloroplast, not microscopic
The answer is C. A theory is an idea intended to explain why something happened. It may have not been proven correct e.g. Darwin's theory of evolution
