A principal difference between prokaryotic and eukaryotic
DNA replication is

a) completely different proteins/enzymes in eukaryotes

b) multiple origins in eukaryotes

c) no requirement for topoisomerase activity in prokaryotes

d) the absence of a nucleus in prokaryotes

Answer Posted / pooja

a)In prokaryotes HU proteins creates negative coiling and
Tus protein terminates DNA replication. Topoisomerase IV
unlinks two circular DNA duplexes. In eukaryotes PCNA
protein prevents PCNA-Rfc-Polymerase delta complex from
dissociating from template. Telomerase are required for
synthesis in end region of lagging strand of DNA. This is
because replication takes place in opposite direction and
DNA polymerase is not capable of adding nucleotides in end
region.

b)Origin of replication always takes place from OriC. This
region is A-T rich. This is because there is double bond
between A and T it would require less energy for breakdown
compared to G-C. Probability of DNA replication to initiate
depends on presence of these nucleotides.

c)HU protein creates negative supercoils in prokaryotes.
Inorder to remove these supercoiling DNA gyrase(belongs to
class topoisomerase)is required.

d)In prokaryotes nucleus is not present, genetic material
is present within the nucleoid.

Is This Answer Correct ?    10 Yes 2 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is the tertiary structure of a protein? What are the main types of tertiary structure?

575


What are the favorable conditions for formation of Anions?

639


What is the name for magnesium per chlorate and what is its formula?

577


What are respectively some remarkable functions of insulin?

554


Garnet is the ore of which element. Give its chemical formula.

610






I have given the protocol for the cyclodextrin glygosyl transferase assay: One ml of appropriately diluted enzyme sample was incubated at 60 °C for 15 min with 5 ml of 1% (w/v) gelatinized soluble starch in 50 mM, 7.0-pH Tris–HCl buffer. Reaction was terminated by boiling the reaction mixture for 3 min and reaction volume was made to 10 ml with distilled water. Two ml of above reaction mixture was withdrawn and mixed with 3 ml of Tris–HCl buffer, 5 ml of 125 mM Na2CO3, and 0.5 ml of phenolphthalein (25 mg phenolphthalein/100 ml absolute alcohol). Absorbance was measured at 550 nm. The percent decrease of sample was calculated with respect to control containing 5 ml of buffer, 5 ml of sodium carbonate and 0.5 ml of phenolphthalein. where Acontrol = absorbance of control and Atest = absorbance of sample. The amount of β-cyclodextrin (β-CD) produced was estimated from the standard graph of 0–500 μg/ml β-CD concentration against % decrease in absorbance. One unit of CGTase was defined as the amount of enzyme required to produce 1 μm of β-CD/min. Please can you suggest me the formula for the defination given in the last line

1704


Why is not it correct to assert that dna self-replicates?

559


what is your passion?

1499


What is the constitution of proteins?

575


What is the structure of cscl and give the co-ordination number of Cscl?

650


Who were james watson, francis crik and maurice wilkins?

657


What are pentoses?

578


Explain who proposed law of mass action? What does it states?

580


Differentiate between gram +ve and gram -ve bacteria.

584


How many sigma and pi bonds are present in nitrogen formula?

628