There are several things that can help scientists evaluate which category something belongs to. The similarity in features is one of them. If two skulls looked alike, they were probably species of the same evolutionary category. For example say humans and monkeys rather than humans and dogs.
Similarly fossils have helped scientists categorise species. Study of the chromosomes (in cases with available chromosomes) can help scientists figure out a lot about the subjects and categorise them.
A cell is like a factory in many ways.
For one, the cell typically contains many organelles that have several varying functions. In a factory, you have many workers who perform different tasks, just as the organelles in the cell do.
Another reason is that cells contain a nucleus or the boss/brain of the cell. In factories, this could be considered the boss of the workplace that tells each and every worker, or organelle, what to do.
The selectively permeable membrane of a cell also resembles a factory as it only lets in workers or special guests. The cell's membrane only lets in specific materials, hence the selectively permeable membrane.
These are just a few ways as to how the cell is like a factory.
Hope this helps!
The correct answer is that chemical changes form new compounds. Chemical change is a change where the substance changes in identity or form new substances after undergoing a process. On the other hand, a physical change is a change in the properties of matter that does not change the identity of the substance.