Which of these characteristics BEST helps scientists classify organisms? A. size
B. color
C. gender
D. structure

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.

Which of the following can be reduced by the use of renewable energy sources? a. social costs b. economic costs c. environmental costs d. all of the above select the best answer from the choices provided a b c d

Which of the following produces carbon dioxide? a. plants b. animals c. decomposers d. all of the above