What is the function of the proofreading step of replication what might happen if this step were skipped?
This proofreading mechanism alone greatly reduces the error rate of DNA replication. proofreading mechanism scans the new strand of DNA for errors missed by proofreading. When errors are found, incorrect nucleotides are removed and replaced by DNA polymerase. This mechanism is called mismatch repair.
What is the function of replication?
DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.
What are the steps of DNA replication in the cell?
There are three main steps to DNA replication: initiation, elongation, and termination. In order to fit within a cell’s nucleus, DNA is packed into tightly coiled structures called chromatin, which loosens prior to replication, allowing the cell replication machinery to access the DNA strands.
What can go wrong during DNA replication?
DNA Damage and Mutations Errors during DNA replication are not the only reason why mutations arise in DNA. Mutations, variations in the nucleotide sequence of a genome, can also occur because of damage to DNA. The most common nucleotide mutations are substitutions, in which one base is replaced by another.
Why is it important that DNA replication is exact?
Why is it is more important for DNA replication to be exact than for transcription or translation to be exact? (1 point) It is more important for DNA replication to be exact than for transcription or translation to be exact because DNA replication produces the master copy which transcription and translation use as the …
What are the 2 major types 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.
What is an example of a beneficial mutation?
Examples of beneficial mutations include HIV resistance, lactose tolerance, and trichromatic vision.
What can cause mutations?
Acquired (or somatic) mutations occur at some time during a person’s life and are present only in certain cells, not in every cell in the body. These changes can be caused by environmental factors such as ultraviolet radiation from the sun, or can occur if an error is made as DNA copies itself during cell division.
What can induce mutations?
Mutations can be induced in a variety of ways, such as by exposure to ultraviolet or ionizing radiation or chemical mutagens. Since the 1950s, over 2,000 crop varieties have been developed by inducing mutations to randomly alter genetic traits and then selecting for improved types among the progeny.
What diseases are caused by silent mutations?
Likewise, silent mutations that cause such skipping of exon excision have been identified in genes thought to play roles in genetic disorders such as Laron dwarfism, Crouzon syndrome, β+-thalassemia, and phenylalanine hydroxylase deficiency (phenylketonuria (PKU)).
What is an example of a missense mutation?
A common and well-known example of a missense mutation is sickle-cell anemia, a blood disease. People with sickle-cell anemia have a missense mutation at a single point in the DNA. This missense mutation calls for a different amino acid, and affects the overall shape of the protein produced.