What conditions cause the contractile vacuole to fill which water?

Which of the following is a testable hypotheses?

Which of these statements is true about autotrophs, but not heterotrophs? a. they use sugar and oxygen to make carbon dioxide and water. b. they use chlorophyll and oxygen to make carbon dioxide and water. c. they use sunlight, water, and carbon dioxide to make sugars. d. they use sunlight, water, and oxygen to make chlorophyll.

Kate is studying the transformation from unicellular to multicellular organisms. which metaphor is the most appropriate to apply to the map of the timeline.