4:
Independent Variable: Photosynthesis
Dependent Variable: Starch
Starch is a product of photosynthesis. Without photosynthesis, starch cannot form. Therefore starch is dependent on photosynthesis.
5:
Independent Variable: Temperature
Dependent Variable: Animal Metabolism
Animal metabolism will only be affected if the temperature of the room changes. Therefore animal metabolism is dependent on temperature.
9:
Independent Variable: Rainfall
Dependent Variable: Thickness of growth rings
The thickness of the tree's growth rings are determined by the amount of rainfall. Therefore the thickness of growth rings are dependent on rainfall.
Below are the choices, the answer is no. 3:
1) The virus was descended from a common ancestor of bird, pig, and human flu viruses.
2) The infected individuals happened to be infected with all three virus types.
3)Related viruses can undergo genetic recombination if the RNA genomes mix andmatch during viral assembly.
4)The human was likely infected with various bacterial strains that contained all three<span>RNA viruses.</span>
The temperature is the independent variable. The independent variable is the variable that the researcher can control. And the dependent variable will change because of the change of independent variable. In this question, the student controls the temperature(independent variable) to see wether the gender(dependent variable) will change due to the temperature.