first let's define null and alternative hypothesis
null hypothesis is a negative hypothesis in which it states that there is no relationship between 2 variables
hyperactivity is unrelated to eating sugar
alternative hypothesis is a hypothesis where it is positive and states that there is a relationship between 2 variables
consuming of sugar or foods containing sugar may cause diabetes and/or cavities
ecosystems have lots of different living organisms that interact with each other. the living organisms in an ecosystem can be divided into three categories: producers, consumers and decomposers. they are all important parts of an ecosystem. producers are the green plants.
i hope that helps! : d