Producers are where the cellular respiration occur in the biosphere.
The independent variable should be the plants you used.
B - the lion eats the grass—it cannot be A. because grass gives off o2 not co2
" As we follow along on a cladogram, it will split at nodes into two or more internodes a specitation event (the formation of new species). The line between two specification events, the internode, represents at least one hypothetical ancestor."
