plays the role in skeletal muscle movement
Microtubules originate on the centre of the cell taking the positive end to the periphery of the cell, while the negative end remains turned to the centre of the cell. The melanosomes move along these microtubules using motor proteins desiganted kinesins and dyneins. The kinesins are responsible for moving the melanosomes to the positive end of the microtubule (periphery of the cell) generating dark-colored cells, whereas dyneins move the melanosomes to the negative end of the microtubule (centre of the cell) generating light-colored cells.
Animals cause erosion in other ways too. When too many animals live in one place, they tend to eat and trample all the plants. Without the plants to protect the soil, it is much more likely to be eroded by wind and water. Animals cause weathering and erosion on rocky shorelines.
