PLEASE HELP You investigate the effect of different concentrations of ethylene spray What would be the independent variable of this investigation?

A the color of the bananas
B the length of ripening time
C the concentrations of ethylene spray
D the age of the bananas

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

Common symptoms of an iron-defiency anemia include muscle weakness shortness of breath and lightheadedness why does iron deficiency causes these symptoms

The cell membrane controls what enters and leaves the cell. which of the structures in the diagram below is the cell membrane? — f оооо