Answer:
A scientific model is a representation model for a certain scientific concept. Scientific models make it easier to study a phenomenon as they tend to model out the exact phenomenons.
A drawing of an skeleton would be unclear as the children might not be able to locate certain features in the drawing. For example, a certain joint could be missed by the teacher in the drawing or the child might not exactly be able to locate where the joint or bone is present.
But as the model will be more real to the actual skeleton system hence, studying through a skeleton will make it a lot easier to study the human skeletal system.
Answer:
ATP stands for adenosine triphosphate. It is a molecule found in the cells of living organisms. It is said to be very important because it transports the energy necessary for all cellular metabolic activities. Without ATP, various metabolic activities in the human body cannot take place.
Explanation:
1. Action potential reaches the axon terminal and depolarizes it.
2. Depolarization opens voltage-gated calcium channels, enabling influx of Ca into the neuron.
3. Calcium binds to specialized proteins on vesicles (containing pre-made acetylcholine) and triggers them to fuse with the neuron membrane at the synapse.
4. Exocytosis of acetylcholine into the synaptic cleft occurs.
5. Acetylcholine diffuses across the synapse and binds to nicotinic receptors on the end plate of the myocyte.
6. Activated nicotinic receptors, themselves ion channels, cause cation influx into the myocyte and generate an end plate potential. This eventually gives rise to the full depolarization within the myocyte that enables contraction.
Invasion and multiplication of pathogenic microorganisms<span> in the body is called an infection. When we are infected by </span>pathogens<span> we become sick, which means that our bodies stop functioning properly. Infectious agents, such as </span>bacteria<span>, a virus, fungi or protozoa cause communicable diseases.</span>