13) Ecologists study how relationships between biotic and abiotic factors impact the many levels of organization on earth. What level of organization is defined as groups of different species that live together in a single ecosystem?
A) organisms
B) ecosystems
populations
D) communities

69 is the correct math for the amino acids

the rocks are classified by the geological process they are formed by. the three main groups of rocks are igneous, metamorphic, and sedimentary. minerals are not they are classified under the chemical classes they are in. these groups include silicates, sulfates and carbonates.

answerhomologous structures;