Answer: The reason is because DNA polymerase which is the enzyme that catalyzes the synthesis of DNA has a 3'->5' exonuclease activity that double-checks each nucleotide after it is added.
Explanation: The 3'->5' exonuclease activity of DNA polymerase allows the enzyme to double-check and remove a newly added wrong nucleotide. It is highly specific for mismatched base pairs. When the DNA polymerase adds a wrong nucleotide to the growing strand, translocation of the enzyme to the position where the next nucleotide is to be added is halted, but the exonuclease activity of the DNA polymerase removes the incorrectly paired nucleotide so that replication can continue. The process of double-checking a newly added nucleotide and removal of any incorrectly paired nucleotide by the DNA polymerase is called proofreading.
Answer:
II. There is an electronegativity difference between the bonded atoms.
Explanation:
In a compound that has a number of individual dipoles(weaker force of attractions between compounds). There exist a weaker intermolecular force of attraction ( Vander waal's forces), these force of attraction arises from fluctuating dipoles in atom molecules brought by the movement of electrons around the atomic nucleus. They possess weak electronegativity difference between the bonded atoms because they have less energy to break these weaker bonds.
Also, individual dipoles can interact with each other in an way which will also increase the boiling point and as boiling point increases there is decrease in electronegativity difference between the bonded atoms.
On the other-hand, A polar compound are ionic compounds and the bonding between them are electrovalent bonding because of their high melting and boiling points. They possess high electronegativity.
Answer:
D
Explanation:
An enzyme called poly (A) polymerase (PAP) is part of the same protein complex that cleaves the pre-mRNA and it immediately adds a string of A nucleotides, called the poly (A) tail, to the 3′ end of the just-cleaved pre-mRNA. The poly (A) tail added protects the mRNA from degradation, aids in the exportation of the mature mRNA to the cytoplasm and helps in binding proteins involved in initiating translation.
Answer:
Explanation:
a fungus named penicillin produces a substance that kills the bacteria near it. The mold produces the antibiotic penicillin. How do fungi help plants grow? The hyphae spread underground and absorb water and nutrients from the soil for the plant.