Of these four scientific designs, choose the one that has a biased design.
1.in a study to determine how bees react to color, both color and light levels are varied.
2.in a study of the effect of temperature on chick hatching times, all variables are controlled except temperature.
3.in a study of the effect of a vitamin on energy levels, the experimental and control groups each have 50 randomly chosen people.
4.in a study of the effect of an antibiotic on bacterial populations, there are several experimental groups at different antibiotic concentrations and one control group receiving no antibiotic.

The correct option is A.

Explanation:

In scientific investigations, there are usually two variables; independent and dependent variables. The value of independent variable is usually changed in order to test its effect on the dependent variables. This means that in a scientific investigation, only one variable should be changed per time in order to determine its effect on the other variable.

In the scenario given in option A, you will notice that the two variables in the investigation were changed at the same time. This is wrong and is an example of a biased design.

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?

i believe your answer would be c.. : )