1. A repeating DNA sequence at the end of chromosomes that prevents them from losing base pair sequences at their ends and from fusing together is called :   A Telomere   A Telomerase   A replicon   None of the above.   Hint Half-n-half Clue   2. The enzyme that creates a short RNA oligonucleotide at initiation sites where replication is to be carried out is called :   Primase   DNA Ligase   DNA Gyrase   Exonuclease   Half-n-half Clue   3. An enzyme (used by all retroviruses) that transcribes genetic information of the virus from RNA into DNA, is :   Reverse transcriptase   RNA polymerase   Restriction nuclease   Methylase   Half-n-half Clue   4. A mamalian cell typically has 1.2 meters (when completely outstretched) of double stranded DNA.The total time to duplicate the DNA is 5 hours. How many origins of replication are there if the rate of duplication is 16µmeters/min ?   250   15000   1   500   Half-n-half Clue   5. An enzyme that recognizes and cuts DNA only at a particular sequence of nucleotides is often called :   Restriction endonuclease   RNA polymerase   Photolyase   DNA glycosylase   Half-n-half Clue   6. The enzyme X removes RNA primers attached by Primase and this gap is then filled in by DNA Polymerase I. The enzyme X is :   RNase H   DNA amylase   DNA ligase   Reverse Transcriptase   Half-n-half Clue   7. In 1940, Nobel Laureate Barbara McClintock discovered sequences of DNA that can move around to different positions within the genome of a single cell and cause mutations. These sequences (first observed in maize) are called :   Transposons   inverted repeats   direct repeats   sticky ends   Half-n-half Clue