That they are <span>caused by microorganisms.</span>
According to the 2011 Earth Science Reference Table, Selenite Gypsum has an approximate hardness of 2.
The hardness of calcite is 3.
The hardness of apatite is 5 according to the Moh's hardness scale.
The hardness of diamond is 10.
<span>indicate a common ancestor exists between two organisms
</span>
NOT:
result from evolution in a similar environment
are features which organisms still have but no longer use
<span>develop when a mutation occurs in the DNA of an organism</span>
We have an internal skeleton and a grasshopper has an external skeleton.
Mitosis produces all animal and plant cells
