$DNA$ polymerase enzyme is responsible for the synthesis of

$DNA$ replication is semi-conservative as

Which of the following sequences is found in Rous sarcoma virus?

$E. coli$ bacteria grown in ${}^{15}NH_4Cl$ medium for several generations are allowed to grow in ${}^{14}NH_4Cl$ medium. After $2$ generations,the density gradient of the isolated $DNA$ is:

Self-replication occurs in

In a nucleus,the number of ribonucleoside triphosphates is $10$ times the number of deoxyribonucleoside triphosphates,but only deoxyribonucleotides are added during $DNA$ replication. Suggest a mechanism.