1- In the cell cycle the mitosis and meiosis are occurring during. done during. Prior to... G1/cytokinesis/G1 a) b) S/G1/GO c) G2/GO/ S d) None of the above/ GO/ G1 and cell repair is

3) The tumor suppressor protein Rb regulation of the entry into the S phase of the cell cycle is represented in this diagram. DNA Answer: b) Explain your choice above: Answer: Rb E2F Genes needed for S phase are NOT transcribed Growth factor Ras pathway Cdk-cyclin 30 ATP ADP Phosphorylated Rb protein P Rb E2F Gene transcription a) In hereditary retinoblastoma tumors, Rb is mutated. Among the following mutations, which one is not likely to be found in these tumors. 1) Mutation prevents Rb to bind E2F by modifying the binding site. 2) Mutation prevents Rb to be dephosphorylated and recycled (possibly by prevented phosphorylated Rb to be recognized by the phosphatase that removes its phosphates). 3) Mutation may cause Rb to be misfolded and not have a functional conformation 4) Mutation that prevent Rb to be phosphorylated by cdk-cyclin. 5) Mutation may cause Rb to be unstable and degraded rapidly. c) (4 pts) Human papilloma virus (HPV) infections are the main causes of cervical cancers.…

At the end of which phase(s) of the mitotic cell cycle does each chromosome consist of two sister chromatids? Indicate all correct answers – more than one answer is correct. a) G1 of interphase b) G2 of interphase c) anaphase  d) metaphase e) prophase f) telophase

What is the significance of the cell cycle control system and checkpoints? Explain step by step in your own words. [please make it simple]