CORRECT ANSWERS: “Eye color is controlled by many genes” and “Eye color has a polygenic inheritance pattern”
***These two answer choices are actually saying the same thing. (poly = many, so polygenic just means a trait is controlled by many genes) These are the best answers because traits that are controlled by several genes have many different phenotypes (traits) that can result (ex: blue eyes, green eyes, brown eyes, hazel eyes...etc).
WRONG ANSWERS: “Eye color is controlled by only one pair of genes”
***The trait is most likely controlled by more than one pair of genes because there are three different phenotypes discussed in the problem. There are inheritance patterns where one gene can cause three phenotypes (complete dominance and incomplete dominance), but these produce a combination of the traits (brown AND blue eyes...doesn’t make much sense) or a mix of the traits (whatever color brown mixed with blue gives you...still probably not green). Anyways, it’s a feasible answer but definitely not the BEST.
“Eye color is not an inherited trait”
***All traits are determined by the genetic code we inherit from our parents. The way our cellular mechanisms express of those traits can vary and be determined by environmental factors, but this is still by far the least accurate statement.
“Eye color is inherited from only one parent”
***For any given gene we receive one allele (copy of that gene) from each parent. Therefore, all of our traits are inherited from both parents. Again, the expression of those traits varied based on patterns of inheritance, environmental factors...etc, but this is another very poor answer choice.
