Which structure in some animals functions at the same level of organization as the kidney and heart?

Creation of an unnaturally uniform sample to represent a diverse populationcan be avoided by: a. including only willing b. asking another scientist for .c. choosing only identical participants.d. selecting individuals at random.

Which of the following is not a food produced in rainforests? a) coffee b) cocoa c) avocados d) wheat

The transport tubes for food coming down the plants are called?