In an ecosystem, organisms can be divided into producers and consumers. Producers are organisms that use sunlight directly for food. Consumers are organisms that eat producers. At which level(s) do producers inhabit the energy pyramid above?

A.

Level 1 (bottom)

B.

Levels 2 and 4

C.

Level 4 (top)

D.

Levels 1 and 2

Study island question

When analyzing tree rings, what do scientists assume a thin ring indicates?

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.

Fungi are classified into how many groups? a. 1 group b. 2 groups c. 3 groups d. 4 groups