Question

true or false

Telomeres are short repeats added to extend the 5' ends of the chromosomes by the telomeres enzyme which is made up of a protein and an RNA that is a template

Theta replication is a type of replication that is observed only in small circular DNA molecules like the bacterial plasmids but not in circular and linear chromosomes of bacteria and eukaryotes

true or false

Answer 1

1. False.

Short repetitive regions at the ends of chromosomes are called telomeres, found in a wide range of eukaryotic species (from human beings to unicellular protists). They act as caps that protect the internal regions of chromosomes. Telomeres prevent the loss of genes as chromosome end tends to wear down. It consists of hundreds or thousands of repeats of the same short DNA sequence repeats, which will varies between organisms but is 5'-TTAGGG-3' in humans and other mammals.

Telomerase is a ribonucleoprotein complex with RNA-dependent DNA polymerase activity. It is a specialized reverse transcriptase which mediates the synthesis of guanine-rich DNA repeats onto telomeres.

Telomerase adds complementary RNA bases to the 3′ end of the DNA strand. Once it is sufficiently elongated, DNA polymerase will add the complementary nucleotides to the ends of the chromosomes.

2. True.

Theta replication can only seen in bacterial plasmid. Theta is an intermediate structure formed during the replication of a circular prokaryote DNA, two replication forks can proceed independently around the DNA ring. If viewed from above, it resembles the Greek letter "theta" (θ). It is the most common mode of bacterial DNA synthesis.

-Origin of replication -Openning of double helix 0.0 este Biduectional replication

Thank you.