When a muscle cell receives a signal from a motor neuron, every sarcomere within that muscle cell is activated. The signal moves from the motor neuron to the muscle cell by crossing the synapse. When acetylcholine binds the sodium enters the T tubules and this causes calcium to be released from the sarcoplamic reticulum. Calcium binds to tropomyosin, which allows actin to bind to myosin and each sarcomere contracts. There is nothing and no way to separate individual sarcomeres. They are all activated together.
They have definite volumes, but no shape, they can change shapes based on the shape of the container.
A. Metals
Metals do not have a basis of carbon
Interspecific competition can occur between two different species competing for the same resource in an ecosystem. So for this particular bug population, there may be another insect species that competes for the same food source or another resource, such as material or space for breeding habitat. This can lead to selective pressure, and may result in the different species evolving a more specific diet or inhabiting a niche environment.
