Some examples of skills used in science include Observation and Measurement. Observational Skills and Measurement Skills.
José probably doesn't feel any pain because his body, during and after exercise released endorphins which are endogenous opioids. This endorphins promote a sense of satisfaction and pleasure, and make pain and discomfort feel irrelevant.
Answer:
<em>The principle of common descent states that all organisms in the world exist because of a common ancestor which gave rise to all the life seen on Earth. The organisms which are more closer to one another might have a common ancestor in the near past as compared to other organisms. The organisms which share distant common ancestors have less common characteristics. This principle has led us to form the basis for the formation of evolutionary biology. </em>
I'd say, ina general way, that the most imporant cells in defense against parasitic organisms are definitely white blood cels, the cells responsible for defeating antigens, pathogens and deseases.
Although these might be the most important ones in that specific task (defending against parasitic organisms), all the cells in the immune system, along with other non-cell things are important, since they all play a specific role indispensable in our immune system.
Hope it helped,
BioTeacher101