Answer:
Causal association is defined as two events in which one event leads to the cause/development of the second event such as the consumption of trans-fats and the onset of heart disease. In order to show the causal association, it is necessary to ensure that the 3 criteria of temporality, consistency, and strength are satisfied with respect to the relationship between consumption of trans fats and heart disease. According to this example involving the relationship between trans-fats and heart disease, temporality could be satisfied if one is consuming an excessive amount of foods containing trans-fats such asFrench fries, and who then ends up suffering from heart disease. In order to fulfill the criteria of strength, statistical tests would need to be performed in order to establish that there is a positive correlation between the individuals who consume trans-fats 10 times per week are shown to develop and require treatment for heart disease 90% of the time. Lastly, consistency may be fulfilled by showing that the same results are occurring despite applying the same testing measures on different groups of individuals during various increments. By applying the same tests on different groups, the chances of creating false-positives within the study can be significantly lowered. Numerous studies can be used to determine whether meaningful statements regarding the causal relationship between two factors can be established. By performing multiple studies on individuals’ eating habits and their health outcomes, researchers may then determine whether a relationship exists between the health challenges that they are faced with and the items that they consume.
Explanation:
The sole reason why red blood cells are unable to replace damaged proteins is that red blood cells lack DNA and cell organelles such as nucleus, ribosomes and mitochondria which are crucial for protein synthesis, assembly and repair. In other words they lack both the information and the machinery for making or repair of proteins.
Due to lack of DNA and cell organelles, red blood cells cannot be able satisfy the central dogma which summarizes synthesis of proteins as DNA → RNA → proteins.
DNA has the genetic information on how proteins should be made, RNA is responsible for transferring the information from DNA in the cell nucleus to the ribosomes in the cytoplasm, then translating or decoding this information, which results in the making of protein.
C. Ice is less dense than water which means water condenses when it freezes allowing the ice in a lake to float on top of the water preventing the water below from freezing.