Mitochondria and chloroplasts likely evolved from engulfed prokaryotes that once lived as independent organisms. At some point, a eukaryotic cell engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host eukaryote, gradually developing into a mitochondrion.
Breaks down rock and carries away fragments
Most shells that are found on beaches are the shells of marine mollusks, partly because these shells are usually made of calcium carbonate, and endure better than shells made of chitin. Apart from mollusk shells, other shells that can be found on beaches are those of barnacles, horseshoe crabs and brachiopods.
B. or A. because you cant use roots to crush and soil is just dirt that isn't strong to crush
Answer - The independent variable is the Temperature which is being changed.
Reasoning - If he changes the temperature on the female and male which is what he is going to test. Then it is the independent variable.
