Population Density and Tadpole Growth
Chapter 36: Populations and Communities

The students in a biology class captured tadpoles in a nearby pond. They put 5 tadpoles in an aquarium filled with pond water (Tank 1) and 60 tadpoles in an identical aquarium (Tank 2). They added the same amount of algae-the tadpoles' food source-to each aquarium. Once a week for the next seven weeks they measured the body mass of each tadpole. They stopped measuring body mass when all the tadpoles turned into frogs. Their data are shown in the table. Use the table to answer the questions.

Average Body Mass of Tadpoles

Week	Tank 1	Tank 2
0	0.10	0.10
1	0.30	0.15
2	0.65	0.20
3	0.90	0.33
4	0.85	0.48
5		0.62
6		0.78
7		0.80

Analyze the Table

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1. Which population of tadpoles grew faster?
   How do you know?
2. Which population reached the higher average body mass?
3. How many weeks did it take the tadpoles in the 5-tadpole population to turn into frogs?
   How much longer did it take the tadpoles in the other population?
4. Why do you think the two tadpole populations showed these differences in growth?

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