why prokayotes don't need primer in DNA replication, why eukaryates need it?

Answer 1

Bacterial chromosomes contain a single origin of repliction in their circular chromosomes. Eukaryotic organisms contain multiple origins in their linear chromosomes.
Replication proceeds bi-directionally in units called Replicons. There is one in bacterial chromosomes and
between 500 - 1000 replicons in eukaryotic chromosomes.
Many of them are not always active at every mitosis.
New strands are synthesized in the 5’ to 3’ direction
5’ end of new strand synthesized first. The leading strand is synthesized continuously while the lagging strand
is synthesized discontinuously. These pieces are called
Okazaki fragments which are joined later.
Bacteria require the following requirements for replication:

1. All 4 nucleotides A,T,C,& G
2. Single strand DNA template strands
3. Proteins that will work on the replication fork such as
unwinding, relaxing, and stabilizing proteins.
4. Short RNA primer to initiate replication
5. DNA polymerases to add to the new strand and proof read the results.
6. DNA Ligase seals gaps in sugar-phosphate backbone connecting the Okazaki fragments.

Answer 2

Prokaryotes DO need a primer. Why do you think they don't?

Edit: the circularity of bacterial DNA is not at issue. Whether the replication is unidirectional or bidirectional you still need the RNA primers to start the process. For the leading strand only one primer is needed, on the lagging strand you need one for every Okazaki fragment

Answer 3

Most prokaryotes have circular DNA, and they have one point of origin. DNA replication can go both ways from the origin.

Answer 4

I believe the reason has to do with the fact that prokaryotes have circular DNA and only one point of origin and eukaryotes have linear DNA and multiple points of origin.