In: Biology
Answer -1
An Operon is a set of structural genes which are regulated by a common promoter. It is an arrangement of genes commonly found in prokaryotes. for example, Lac Operon, which is responsible for the metabolism of lactose in bacteria has a single promoter and the Three genes which are regulated by this single promoter lacZ, lacY, lacA.
The most important advantage of this type of gene arrangement is that more than one genes can be transcribed in one go.
The disadvantage if that if the promoter is mutated, then all of the genes will not be transcribed and the whole Operon will be shut down
Answer- 2
Two strands of DNA run in the antiparallel direction.
During replication, the replication fork is formed by opening up the two strands and synthesis of DNA on top of the existing strand will start in 5' to 3' by DNA polymerase.
One of the strands is continuously replicated as the DNA polymerase can proceed only 5' to 3'.
The other strand (lagging strand) needs to be replicated in the opposite direction.
Therefore, short fragments of DNA are produced as the replication fork expands.
Hence this is a discontinuous synthesis.