- Different species of organisms have different inherited characteristics
- The size of an organism is an inherited characteristic
- Therefore, different species of organisms will have different inherited characteristics in size

- Different species of organisms will have different inherited characteristics in size
- Genes are able to determine the inherited characteristics of a living thing
- Therefore, different species of organisms have different genes determining the size

- Different species of organisms have different genes determining the size
- Tigers and household cats are different species
- Hence, genetic difference in tigers and cats determines the difference in size

So, genetic difference in tigers and cats determines the difference in size
[Question]Tigers and household cats are members of the same family; however, their sizes are vastly different. What is the cause of this difference?
[Context]- Different species of organisms have different inherited characteristics 
- Tigers and household cats are different species 
- Genes are able to determine the inherited characteristics of a living thing 
- The size of an organism is an inherited characteristic