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:
The action potential is conducted into a skeletal muscle fiber by, transverse tubules.
It is much likely that the mother will suffer from pneumonia. Fetus is likely to suffer from birth defects known as varicella syndrome if it occurs at a gestation of 8-20 Wks (skin scaring, underdeveloped arms and legs, incomplete brain development)
if the infection is within 48yrs before a delivery child may suffer from neonatal varicella which is life-threatening
