Answer:
A controlled experiment is simply an experiment in which all factors are held constant except for one: the independent variable. A common type of controlled experiment compares a control group against an experimental group. All variables are identical between the two groups except for the factor being tested.
Explanation:
Energy is an ecosystem flows only one way.
Energy flows through an ecosystem in only one direction as it is passed from organisms at one trophic level or energy level to organisms in the next trophic level.
alleles may be codominant—i.e., neither acts as dominant or recessive. An example is the human ABO blood system; persons with type AB blood have one allele for A and one for B. (Persons with neither are type O.)
