The most common example that determines the similarities in anatomical features among organisms is the bone structure, commonly used in comparative anatomy. For example, the forelimbs or appendages of bats, humans, cats and whales have the same basic parts but they differ in function. Fins of whales and wings of bats have the same skeletal parts, but fin is used for swimming while wing is for flight. These structures could be termed as homologous, analogous, or homoplastic. However, recent developments have been made than just basing to the skeleton - the main reason why we have comparative genomics today.
Chemical weathering is decomposition of rock caused by chemical reactions resulting in formation of new compound. Weathering breaks down and loosens the surface minerals of rock. Hence, the broken rocks are transported to another place where it decomposes and forms soil. Therefore weathering is important for soil formation. Chemical weathering is decomposition of rock caused by chemical reactions resulting in formation of new compound.
I only know the first one .Your teeth helps chew things to make it easier to digest in your stomach , which goes through your throat to your stomach. Your mouth uses muscles for the motion and movement for your teeth to chew.