The Cell Cycle, Mitosis, and Apoptosis

Question 1

Explain the primary cellular events associated with each stage of the cell cycle

Answer 1

Prophase - chromosomes condense and mitotic spindles begin to form, centrioles form
Metaphase - chromosome are aligned in the middle
Anaphase - centromeres separate to opposite poles of the cell
Telophase - cytokinesis

Question 2

Explain the role of cyclin and cdks in progressing through cell cycle checkpoints

Answer 2

Cdks are turned on by cyclins at the appropriate time. Cyclins fluctuate over time and are gene products that govern the transition from on phase of the cell cycle to another.

Question 3

Explain the difference b/w oncogenes and tumor-suppressor genes

Answer 3

Oncogenes - altered forms of normal genes
Proto-oncogenes - have key roles in cell growth and differentiation

Tumor Suppressor Genes - group of cloned hereditary cancer genes. Suppress inappropriate cell proliferation
Ex: p53 - plays a major role in the activation of apoptosis, RB1 - associated with DNA and is involved in the regulation of the cell cycle

Question 4

Explain how a proto-oncogene is diff from an oncogene, giving a description of how a proto-oncogene is different from an oncogene, giving a description of how a proto-oncogene can become an oncogene

Answer 4

Protooncogenes may become oncogenes through: viral transduction, errors in replication or retrovirus genome, or random mutation