Answer: it makes generic embryonic cells become specialized cells through a process known as gene expression.
Explanation:
If we guide ourselves with the Moh´s scale:
Material scratches apatite → material is harder than 5.
Material is scratched by corundum → material is softer than 9.
Conclusion:
The hardness of the unknown material stands between 5 and 9.
Note:
Both apatite and corundum are defining materials (reference materials in the Moh´s scale). So, you can also give an answer using defining materials:
"It can either be an orthoclase feldspar, a quartz or a topaz".
Hope it helped,
BiologiaMagister
<u><em>This answer is dedicated to JaySL</em></u>
A) Biological, physical, and chemical.
b) Physical: sediment radioactive material and heat.
c) Chemical: organic/inorganic: heavy metals, nutrients & pesticides.
Because there are children in africa starving... Duhhh!!!!!