Ecosystems and material cycles: Practice Questions

In the carbon cycle, which of the following biological processes is responsible for the fixation of atmospheric carbon dioxide into organic molecules?

Nitrogen-fixing bacteria play a vital role in the nitrogen cycle. In which part of the ecosystem are these bacteria most commonly found living in a mutualistic relationship with legumes?

A student uses a quadrat to estimate the number of daisies in a field with a total area of \(200\text{ m}^2\). They place a \(0.25\text{ m}^2\) quadrat \(10\) times and find a mean of \(4\) daisies per quadrat. What is the estimated total number of daisies in the field?

Fish farming is a human interaction intended to meet food demand, but it can negatively impact local biodiversity. Which process is most likely to occur in surrounding waters if excess fish food and waste leak into the environment?

Which of the following describes a biotic factor that would lead to a decrease in the size of a rabbit population?

A student uses a quadrat to estimate a population of daisies. They find an average of \(4\) daisies per \(0.25\text{ m}^2\) quadrat. Calculate the estimated total population in a field measuring \(20\text{ m}\) by \(50\text{ m}\).

Evaluate the role of bacteria in the nitrogen cycle, specifically identifying the different types of bacteria required to convert nitrogen gas into a form usable by plants and back into the atmosphere.

Explain how human activities can lead to the eutrophication of a lake. In your response, describe the specific roles of nitrates, algae, and decomposers in the carbon cycle within this ecosystem, and how this process impacts biodiversity.