How are the structures of compact and spongy bone different? how are they similar?

Check all that apply diatoms are marine algae that have a shell made of silica, what are some of the uses of the silica shell after the diatoms die? 1.the shells make up the diatomaceous earth used in filters 2.it can be used as an ingredient in abrasives 3.they are used in food products 4.the shells can be used in some insulating materials

Ascientific idea becomes valid when it is what?

Is genetic diversity the same as genetic variation?