Question

During DNA replication in prokaryotes, DNA is anchored by
A. Chromosome
B. Mesosome
C. Nucleolus
D. Ribosome

Answer 1

Hint: Prokaryotes lack membrane-bound organelles in their cells. Their plasma membrane is extended into the cytoplasm to provide the surface for various metabolic pathways. As prokaryotes lack mitochondria, the extensions of the membrane also serve as a site for cellular respiration.

Complete step by step answer: Prokaryotes are the organisms characterized by the absence of a well-defined membrane-bound nucleus. Their DNA lies free in the cytoplasm in the region called the nucleoid. The Nucleolus is the structure present inside the nucleus of the eukaryotes that is rich in proteins and the ribosomal DNA. The nucleolus is the site for the synthesis of ribosomal RNA and the assembly of the ribosomal subunits in eukaryotes. Since prokaryotes lack a nucleus, they also lack the nucleolus.
Ribosomes are the complexes of proteins and rRNAs (ribosomal RNAs). Ribosomal proteins and the rRNA organize to make small and large ribosomal subunits. The mRNA formed by the transcription of DNA joins the ribosome to begin the process of protein synthesis.
Chromosomes are the thread-like structures composed of chromatin. Chromatin is a complex of DNA and the packaging proteins. Chromosomes become visible during the early stages of cell division due to the condensation of chromatin.
To facilitate DNA replication, the origin of replication in prokaryotes becomes attached to the mesosomes while other strands join the cytoplasmic membrane to form a new mesosome. Mesosomes are the cytoplasmic extensions of the prokaryotic plasma membrane. The replication-associated enzymes join the DNA and the unwinding of DNA helix at the origin of replication separates the two DNA strands. DNA polymerase joins the complex to form the complementary strands on the DNA template strands resulting in the formation of two daughter chromosomes.
So, the correct answer is option B. Mesosomes.

Note: Since DNA in prokaryotes is present in the nucleoid, DNA replication occurs in the cytoplasm only. DNA replication in prokaryotes starts with the separation of the two DNA strands to form the Y shaped replication fork. In bacteria, the origin of replication of the newly formed daughter chromosomes are attached to the individual mesosomes at the end of the replication.