A mother and father have two daughters. The daughters have some similar and some different physical features. Which statement BEST explains why the girls’ physical appearance includes both similar and different features? Group of answer choices

the daughters received a random set of genes from both parents

one daughter received fewer genes than the other

each daughter received a different number of genes from each parent

one daughter received all her genes from her father and the other daughter received all her genes from her mother

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol