Bacteria and fungi are found in all ecosystems on Earth. A scientist claims that fungi are keystone species in a particular terrestrial ecosystem. To test this hypothesis, the scientist divides an area within the ecosystem into multiple small plots of similar size. Equal numbers of plots are then randomly assigned to one of three treatment groups. Plots in the first group are sprayed with a water-soluble substance that selectively kills fungi. Plots in the second group are sprayed with a water-soluble substance that selectively kills bacteria. Plots in the third group are sprayed with the same volume of water only. After a certain period of time, the scientist then measures the amount of accessible nutrients in the soil in each plot.

Required:

a. Describe ONE common role of both bacteria and fungi in the movement of energy and matter in ecosystems.
b. Describe how analyzing the data from the treatment group sprayed with water only will increase the validity of the experimental results

B) The treatment where only water is used has more nutrient concentration as compared to other plots increase the validity of the experimental results.

Explanation:

Saprophytes are those organisms which has the ability to broken down the dead bodies of plants and animals in the soil and increase the nutrients concentration in the soil. Examples of saprophytes are bacteria and fungi. Saprophytes are also known as decomposers. The treatment where only water is used has more nutrient concentration as compared to other plots because the other two plots has low population of fungi and bacteria due to the use of chemicals that kills bacteria and fungi while the population of fungi and bacteria is high in the plot where only water is applied. So that's why increase the validity of the experimental results.