Will up vote
what is the role of the dna polymerase in dna replication?

a. it ties the chunks of dna together.
b. it checks the dna for errors.
c. it creates the replication fork.
d. it breaks apart the bases

Ok, DNA Polymerase is an enzyme that joins free nucleotides to both existing strands of DNA, which means it isn't D (which is helicase, by the way). They normally work in pairs of two for this function, so it isn't C; this is because if it created a fork, there would only be one needed. Now, concerning A & B, you'll have to be careful. Depending on how A is worded contextually, it could be correct, or it could not. I'm not sure I like the wording "chunks." Which is why I think it's B. Polymerase joins one strand of the "unzipped" DNA to free nucleotides that match it, and these aren't "chunks of DNA." Now, Polymerase is VERY accurate, only making a mistake once every millionth (or billionth?) nucleotide matchup. When it does make a mistake (most of the time), it'll go back and fix it. So I believe the best answer is B, it checks for errors.
Hope this helps!

The probability of a hit that includes home runs is 127/369 and the probability of a home run is 21/369 = 7/123. The probability of a hit that is not a home run is (127-21)/369 = 106/369 while the probability of no hit is (369-127)/369 = 242/369. Therefore, the expected value of his score at each at bat is(0) 242/369 + (1) 106/369 + (5) 21/369.106/369 + 105/369 = 211/369 = 0.572