Water was the only type of life on the planet for hundreds of million of years
They carry on different on jobs to help the cell work. For example, mitochondria produces energy from the oxidation of glucose.
The tumor suppressors allele is analogous to the brake pedal in a vehicle while cyclins are like the gas pedal. The tumor supressors regulate, negatively, the replication of cells. If the tumor supressor is mutated, this is analogous to the brake pedals of the vehicle being broken, This means that if two are broken, then the vehicle will be unable to stop and will continue moving. This same way, if tumor suppressors are mutated, the replication of cells will continue unregulated and casue a tumor.
Answer:
When helicase mutations occur, problems in DNA replication are found. The helicases are proteins that open the 2 strands of DNA to initiate the duplication, they are responsible for breaking the hydrogen bonds between the two DNA chains, thus separating the chains, also they have the function of repairing DNA mutations, if there is mutation in the gene that encodes them, various functions will be absent in the cell.