Dr. Bert Vogelstein and his partners study the causes of cancer. In 2017, they published a study of 32 types of cancer. The stud
y concluded that most cancer cases are caused by DNA replication errors. In fact, 66% of the cancer cases they studied were caused by random DNA replication errors. Environmental factors such as diet, sunburns, and smoking caused 29% of the cancers. The last 5% of cancers in the study were caused by inherited factors. Briefly describe the steps of DNA replication and point out one place in the code where an error can occur.
Error or mistakes during DNA replication is accountable for two-thirds or 66% of the cancer cases. These random and unpredictable errors called mutations that occur during the division of a cell as an error in copying of DNA.
DNA replication has three main steps:
Opening and separation of DNA strands of a helix - carried by an enzyme known as helicase that breaks the hydrogen bonds between nitrogenous bases of the helix of DNA.
The priming of the template strand - DNA primase helps RNA primers to bind to both strands at 3' end as soon as it separated
strat assembling the segments of new DNA on strands called elongation of the strands with help DNA polymerase I and after forming new strands the termination of the replication.
Errors or mistakes can occasionally take place if DNA polymerase inserts a wrong base during elongation of the strands.
Density of a solution is mass of solution per unit volume Density = mass/volume mass of solution is 46.08 g volume of solution is 58.9 mL since mass and volume is known, density can be calculated density = 46.08 g / 58.9 mL = 0.78 g/mL
Moles of CO2 = number of molecules / 6.02x10^23. = 3x10^23/6.02x10^23 = 0.5moles. Therefore, mass of CO2 = moles x molecular mass of CO2= 0.5x44 = 22gm.
