Answer:
Explanation:
Muscle contraction is stimulated by the movement of an action potential moving along a nerve fiber to the muscles. This event follow some series of process before being stimulated.
1. The impulse arrives at the synapse and travels through the transverse tubules.
2. The muscle impulse reaches the sarcoplasmic reticulum and calcium is released.
3. Calcium floods the sarcoplasm and binds to troponin molecules leaving active sites.
4. Tropomyosin molecules bind to exposed active sites, linking actin and myosin.
5. Thin filaments are pulled over the thick filaments.
6. The muscle fiber shortens and contracts.
Answer:
Channels discriminate between solutes mainly on the basis of size and electric charge.
Explanation:
Answer:
Well there are many ways for scientific models to be use like if something was small and you couldn't see it u would have to make a model of that
Explanation:
If this didn't help I'm sorry
I think one is carbon dioxide not sure what the other is
The best answer is b - it is rigid.
The cell wall is defined as the rigid, outermost layer found in plants and also certain bacteria, algae and fungi. It is absent in animal cells.
The plant cell wall is made up cellulose which is a structural carbohydrate. The cell wall is rigid and thus offers structural support allowing plant such as trees to grow to great heights.
It also helps prevent water loss, helps protect against insects and pathogens and keeps the shape of the plant.
