Neurons and muscle cells perform different functions. In the body, these cells have the same . The function of muscle cells is , while the function of neurons is to send nerve signals.

Nerve cells and muscle cells are excitable because their cell membrane can produce electrochemical impulses and conduct them along the membrane.

Explanation:

the reason the two sea urchins don't compete with each other for food, resources, etc. is because the urchins have adapted to the environment but they have also adapted to each other. this is most likely because the genes of the sea urchins.

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

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