1.Stomata are: A)pores in plant cells
B)pores on the leaves of a plant
C)photosynthetic organ
D)none of the above
2.Blue black coloration on leaves during test for photosynthesis is
A)confirmation of release of oxygen
B)confirmation of carbohydrate formation
C)confirmation of the formation of Water molecules
D)None of the above

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

!if we removed the wolf, snake, and hawk from this food web, what best explains the impact it would have? a) the number of producers would increase. b)the number of decomposers would increase. c)the number of primary consumers would increase. d)the numbers of primary consumers would decrease.

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis