How does DNA polymerase aid in accurately copying DNA?
Every time a cell divides, DNA polymerase is required to help duplicate the cell’s DNA, so that a copy of the original DNA molecule can be passed to each of the daughter cells. DNA polymerase adds new free nucleotides to the 3′ end of the newly-forming strand, elongating it in a 5′ to 3′ direction.
Which DNA polymerase removes RNA primer and replaces it with DNA?
Because of its 5 to 3 exonuclease activity, DNA polymerase I removes RNA primers and fills the gaps between Okazaki fragments with DNA.
What happens if RNA primase is not present?
What would happen if primase were inactivated? DNA polymerase III would not be able to make a complementary strand. Removes RNA primers and replaces them with deoxyribonucleotides during DNA replication.
What are five environmental factors that can cause mutations?
Ionising radiations such as X rays, gamma rays, alpha particles, UV radiations and radioactive decay act as mutagens. Chemical. Chemicals that react with DNA molecules such as alkylators include ethyl methane sulfonate, methyl methane sulfonate, di ethyl sulfonate and nitrosogaunidine. Infectious agents.
What are the two main categories of mutations?
Two major categories of mutations are germline mutations and somatic mutations.Germline mutations occur in gametes. These mutations are especially significant because they can be transmitted to offspring and every cell in the offspring will have the mutation.Somatic mutations occur in other cells of the body.
Which type of mutation has the most deleterious effect on protein function?
Nonsense mutation. A nonsense mutation is also a change in one DNA base pair. Instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. This type of mutation results in a shortened protein that may function improperly or not at all.