Answer:
natural disasters,emigration and scarcity of food
Explanation: natural disasters: this affect population where by organisms leave there area or habitat for another area due to unfavorable conditions eg. flood, bush fire, storms, earthquake etc. and can also lead to death.
Emigration:this is when organisms leave an area for another either in search of food, breeding purpose this reduses population where by organisms may never return.
scarcity of food:this occur when there is insufficiency or no food in an area which makes organisms leave their habitat for another in search of food and might even lead to death.
Protein is made up of subunits and each subunit is made up of polypeptides molecules . Called Amino acids .
The right answer to this question is option C. the traits acted upon natural selection were genes.
At the time Charles Darwin developed the evolution theory, there wasn't a single study about genes in all science scenery, that could be explained by the lack of technology to study them and even to know they existed in the first place.
So, his theory was basically talking about adaptation, if an organism can't survive a specific environment, he'll probably die until another generation comes in and this one can survive in this environment, passing their genes to the next ones. The lack of information was the knowledge about the genes we have today, that's why most scientists take only the new Darwin theory, that includes the study of genes.