Study the timeline. Based on the timeline, about how many years ago could the oldest mammalian organism have lived?

5 million years
200 million years
1.5 billion years
4.5 billion years

This is the process of making a prediction based on the results of prior observations of similar events.

Natural resources are any materials that humans obtain from the earth to meet our wants and needs.

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.