Which of the following substances may NOT pass through the cell membrane freely? oxygen, carbon dioxide, water or proteins

Heredity has an impact on personal health, but environmental factors are important as well. select the best answer from the choices provided

Which would happen if more forests were cut down? a. the nitrogen cycle would be stopped b. nitrogen would be fixed by bacteria more quickly c. the amount of co2 in the atmosphere would increase d. fossil fuels would build up in the soil c the amount of co2 in the atmosphere would increase

Crossing over is a method of (blank)?