Industrially, vanadium metal can be obtained by reacting vanadium(V)oxide with
calcium at high temperatures:
5Ca + V205 → 5CaO + 2V
In one process, 1540 g of V2O5 react with 1960 g of Ca. (a) Calculate the mass of vanadium
formed. (b) How many grams of the excess reagent is left at the end of the reaction?

explanation:

level 4 to level 2 : ))

a) adding base pairs

c) unwinding the helix

there are possible two correct answers for this question.

dna polymerase doesn’t add base pairs, it adds single nucleotides which are complentar to coding strand . also dna polymerase can’t unwind the dna helix alone. dna helicase can do that, using energy derived from atp hydrolysis.

dna polymerase are enzymes that synthesize dna molecules from deoxyribonucleotides. these enzymes replicate the dna strand and create two identical dna strands from a single original dna molecule. some of dna polymerases have a function of correcting erros which are made during replication and this process is called proofreading. if the dna polymerase detects that incorrectly paired nucleotide has been added, it will remove and replace the wrong nucleotide.