CELL CYCLE REGULATION

All links are on my wiki at: Click on AP Biology; Click on Topic 5: Cell Communication and the Cell Cycle ; scroll down to the Cell Cycle Regulation part.

~Use the Biology at Arizona website to learn more about Cell Cycle Regulation and Cancer.

~Watch the two You-Tube videos on my wiki under Unregulated Cell Division.

What is cancer? ______

~Be sure to read through the Course Notes Lecture Outline website also and the Prezi Cell Cycle Control website. Use all websites to finish the following lecture guide.

How do the following regulate the cell cycle?

  • p53?
  • p27?

Internal Controls (what does this mean?)

  • Cyclins and CDK?
  • MPF?

External Controls (what does this mean?)

  • PDGF?

MITOSIS REVIEW

1)The stage of the cell cycle where each chromosome is composed of two chromatids in preparation for mitosis.

  1. G1b. Sc. Md. G2

2)The class of enzymes that are involved in triggering events in the cell cycle are called:

  1. proteasesb. transferasesc. kinasesd. nucleases

3)Which sequence of the cell cycle is common to eukaryotes?

  1. G1 to G2 to S to M to cytokinesis
  2. G1 to M to G2 to S to cytokinesis
  3. G1 to S to M to G2 to cytokinesis
  4. G1 to S to G2 to M to cytokinesis

4)The stage of the cell cycle where the cell is preparing to begin DNA replication is called:

  1. G1b. G2c. Sd. M

5)The proteins which complex with DNA producing the "beads on a string" or nucleosomes are called:

  1. kinasesb. proteasesc. spindle fibersd. histones

6)Which of the following features of cell division are very different for animal and plant cells?

  1. Prophaseb. Metaphasec. Anaphased. Cytokinesis

7)Prior to cell division, each chromosome replicates or duplicates its genetic material. The products are connected by a centromere and are called:

  1. Sister chromosomesc. Sex chromosomes
  2. Homologous chromosomesd. Sister chromatids

8)The first stage of mitosis when chromosomes start becoming visible in the microscope is called:

  1. Anaphaseb. Prophasec. Telophased. Metaphase

9)The sputum (fluid coughed up from the lungs) of many smokers contain cells with mutations (errors) in the genes for p53. The smoking induced mutations appear to be an early signal showing that cancer of the lungs will follow. What is the likely relationship between early p53 mutation and the development of lung cancer?

a. / p53 with a mutation directly stimulates the growth of cancer cells.
b. / Mutations in p53 would prevent abnormal cells from dying by apoptosis.
c. / Mutant p53 triggers the M phase of the cell cycle leading to abnormal cell division.
d. / p53 causes a cell to enter G0, blocking cell division.

10)Which of the following statements is NOT true of mitosis?

a. / A single nucleus gives rise to two identical daughter nuclei.
b. / The daughter nuclei are genetically identical to the parent nucleus.
c. / The centromeres divide at the onset of anaphase.
d. / Homologous chromosomes synapse in prophase.

11)Cytokinesis in a plant cell is characterized by:

a. / the equal division of homologous chromosomes.
b. / a pinching off of the cell membrane to divide the cell.
c. / the formation of a cell plate in the cytoplasm.
d. / the movement of the chromosomes from the metaphase plate.

WHICH PHASE?

HOW DID MITOSIS EVOLVE (use the Course Notes Lecture Outlinewebsite)?

CASE STUDY: Philadelphia Chromosomes

In normal cells, mitosis usually is blocked if there is DNA damage. Sometimes, though, DNA damage makes cells divide more often. Certain forms of leukemia have a unique feature called a Philadelphia chromosome. Look at the karyotype of leukemia cells in the figure below and do some research. Answer the questions that follow. Watch the video on my wiki too!!

Karyotype of a patient with chronic myelogenous leukemia indicating chromosomal deformity.

1)What are Phildelphia chromosomes?

2)What happens in a normal cell if the DNA has mutations?

3)What would happen if cells with mutated DNA replicated?

4)How do cells monitor DNA integrity?

5)How are the chromosomes different in cancer cells compared to normal cells.

6)How could these differences lead to cancer?