Answer:
There are no specified options in this question but the answer will be provided elaborately in order to fully comprehend it.
Please find the detailed answer in the explanation section.
Explanation:
Matter undergoes two types of changes viz: physical and chemical changes. A physical change, as the name suggests, involves a change in the physical nature of matter. A physical change does not change the chemical property of the substance involved. Since there is no chemical modification to the substance, no new substance is formed from a physical change. Hence, the substance only undergoes a change of state. For example, water (liquid) changing to ice (solid) is a physical change. Physical changes are usually reversibleb i.e. can be changed back to their previous form.
Chemical change is another type of change in which substances undergo a change in their chemical properties to form new substances. Changes like formation of gas bubbles, change in temperature, color change etc will be noticed during chemical changes. Examples of chemical changes are rusting, burning because they irreversibly change the chemical composition of the substances involved etc.
In a nutshell, in order to determine the type of change occuring in a reaction, one should look out for whether or not there is a change in nature of the substance leading to the formation or not of a new substance.
Answer:
Theories are ideas and supposition used to explain something, a law is a system of rules in place to regulate actions of their members. Theories are something that can be bent and changed at will. Laws have to be judged in court before someone can change them.
Answer:
The form of cell to cell signalling that is been used is ENDOCRINE.
Explanation:
There are four ways by which cell signalling occur in the body, these are: endocrine, paracrine, autocrine and direct signalling.
Endocrine signalling is the biochemical process by which hormone secreting glands release hormones into the blood streams and that hormone has effects on target organs that are located far away from it. Endocrine hormones are usually stable and their effects usually last for long time.