![whatsittoya4261](/avatars/20888.jpg)
whatsittoya4261
26.07.2019 •
Biology
What do you predict would be the result for a person with an impaired vestibular apparatus? explain.
Solved
Show answers
More tips
- A Auto and Moto Battle for the Relocation of The Cherkizovsky Market: Who Won?...
- F Food and Cooking Homemade kvass: recipe and brewing process...
- O Other What is a Disk Emulsifier and How Does it Work?...
- H Health and Medicine How to Calm Your Nerves? Expert Tips That Actually Work...
- A Animals and plants 5 Tips for Taking Care of Yews to Keep Them Green and Beautiful...
- S Sport How to wrap boxing hand wraps? Everything you need to know!...
- F Food and Cooking 10 Reasons Why You Should Avoid Giving Re-Gifts: An Informative Guide...
- F Family and Home Tender Care for Your Parquet: Is it Possible to Clean Parquet?...
- S Style and Beauty How Are Eyelash Extensions Applied? All Your Questions Answered...
- F Food and Cooking 10 Tips for Proper Sushi Consumption...
Answers on questions: Biology
- B Biology What are the enzymes that cut the dna so that the insulin-producing gene can be removed?...
- B Biology Explain why critical thinking is particularly important when evaluating promotional materials....
- B Biology Which of the following is a characteristic feature of a carrier protein in a plasma membrane? a. it is a peripheral membrane protein. b. it exhibits a specificity for a particular...
- B Biology Which substance is a mixture of organic matter and weathered rock?...
- B Biology Using the image below, match items a, b, c, d, and e with the correct term....
- B Biology What is found running through the pulp cavity...
- B Biology How much time will it take for a person to walk the length of a football field (91 m) at a constant speed of 152 cm/s?...
- B Biology The [rungs] of the dna ladder are made of...
- B Biology Why is color blindness more common in males...
- B Biology Why is the water molecule so important to organisms?...
Ответ:
Ответ:
Key points:
Cells have a variety of mechanisms to prevent mutations, or permanent changes in DNA sequence.
During DNA synthesis, most DNA polymerases "check their work," fixing the majority of mispaired bases in a process called proofreading.
Immediately after DNA synthesis, any remaining mispaired bases can be detected and replaced in a process called mismatch repair.
If DNA gets damaged, it can be repaired by various mechanisms, including chemical reversal, excision repair, and double-stranded break repair.
Introduction
What does DNA have to do with cancer? Cancer occurs when cells divide in an uncontrolled way, ignoring normal "stop" signals and producing a tumor. This bad behavior is caused by accumulated mutations, or permanent sequence changes in the cells' DNA.
Replication errors and DNA damage are actually happening in the cells of our bodies all the time. In most cases, however, they don’t cause cancer, or even mutations. That’s because they are usually detected and fixed by DNA proofreading and repair mechanisms. Or, if the damage cannot be fixed, the cell will undergo programmed cell death (apoptosis) to avoid passing on the faulty DNA.
Mutations happen, and get passed on to daughter cells, only when these mechanisms fail. Cancer, in turn, develops only when multiple mutations in division-related genes accumulate in the same cell.
In this article, we’ll take a closer look at the mechanisms used by cells to correct replication errors and fix DNA damage, including:
Proofreading, which corrects errors during DNA replication
Mismatch repair, which fixes mispaired bases right after DNA replication
DNA damage repair pathways, which detect and correct damage throughout the cell cycle
Proofreading
DNA polymerases are the enzymes that build DNA in cells. During DNA replication (copying), most DNA polymerases can “check their work” with each base that they add. This process is called proofreading. If the polymerase detects that a wrong (incorrectly paired) nucleotide has been added, it will remove and replace the nucleotide right away, before continuing with DNA synthesis