AP Biology

The Cell CyclePart 2

Centrioles

Interphase

Before and after the S phase

Interphase cell (Look at the chromatin in the blue nucleus and the

yellow cytoskeleton.)

Start of Mitosis

Cell in Prophase

Mitosis “Division of the nucleus”

Cell in Metaphase

Cell in Anaphase

Cell in Telophase and starting Cytokinesis

One cell becoming two

Motor Protein and the Spindle Fibers

Chromosomemovement

Microtubule Motorprotein

Chromosome

Kinetochore

Tubulinsubunits

Animal vs. Plant

LE 12-10

NucleusCell plateChromosomesNucleolus

Chromatincondensing 10 µm

Prophase. The chromatin is condensing.The nucleolus is beginning to disappear.Although not yet visible in the micrograph, the mitotic spindle is starting to form.

Prometaphase. Wenow see discrete chromosomes; each consists of two identical sister chromatids. Laterin prometaphase, the nuclear envelope will fragment.

Metaphase. The spindle is complete, and the chromosomes, attached to microtubules at their kinetochores, are all at the metaphase plate.

Anaphase. The chromatids of each chromosome have separated, and the daughter chromosomes are moving to the ends of the cell as their kinetochore micro- tubules shorten.

Telophase. Daughter nuclei are forming. Meanwhile, cytokinesis has started: The cell plate, which will divide the cytoplasm in two, is growing toward the perimeter of the parent cell.

Microscopic view of Mitosis in Onion root tips.Can you identify the stages?

Checkpoints(Is all going according to plan?)

• Question: All organisms must be able to reproduce to keep the species existent. Prokaryotes undergo Binary Fission and Eukaryotic cells undergo Mitosis. In no more than four sentences, explain one similarity and one difference between the two processes. In addition, explain the evolution link between the two processes. (5 Points)

•

• Scoring Rubric: 1pt. Discussion of one similiarity – Cytokinesis, DNA synthesis (S), or Maturion (G1)

• 1pt. Discussion of one difference – G2 or Mitosis• 1pt. Discussion of Binary fission being first and

evolving into Mitosis as DNA and organisms became more complex over time.

• 1pt. Correct use of scientific terms.• 1pt. Answer has no more than three sentences.

(Following Directions.)• • This question addresses Essential Knowledge: 1.B.1