Best Answer: Genotype frequencies are the frequencies of the homozygous dominant (AA) heterozygous (Aa) and homozygous recessive (aa). If you're using population genetics, then they are the p^2, 2pq, and q^2 values.
Petrified fossil is an organism that has been converted into stone.  Silica, iron and copper minerals can be commonly found in petrified  fossils.
Fossils come in two forms: Body fossils and trace fossils. The type of fossil pictured above is a body fossil. In fact, any body part that has petrified (turned to stone) is considered a body fossil. You can see why this type of fossil is often more appreciated; skulls, teeth, claws, and bones all fall into the body fossil category.