Blood typing is an example of this is where there is one gene but that one gene can have several different characteristics

Blood type is an example of  

✔ codominance

.

Blood type is determined by the  

✔ antigens

on the blood cells.

✔ Antibodies

attack foreign blood that does not contain the same antigens.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint