Question

name: siqing luo (isabel) date: 10/03 period: 6th. cell cycle, mitosis & cancer due date: using the labeled cell cycle diagram to the right do the following: left column: place the corresponding letter for the correct stage right column: complete the description of the stage in the 1. a : consists of g₁, s and g₂ phases in the cell cycle. 2. _ cytokinesis - division of the cytoplasm resulting in two identical d__ cells. 3. _ g₁ - growth phase: makes organelles and proteins needed for replication of dna. also contains a g₁ checkpoint. if everything is correct, cell will proceed to s phase. 4. _ s phase: dna is replicated or synthesized. 5. d g₂ - growth phase: cell gets ready to undergo m. also contains a g₂ checkpoint. if dna replication is correct, checkpoint allows cell to enter m phase. 6. _ prophase: chromatin condenses to become chromatin, nuclear envelopes breaks down, and centrioles migrate to opposite poles in animal cells. nucleolus disappears. 7. _ m: sister chromatids line up along the metaphase plate in the middle. spindle apparatus attaches at the centromere of the chromosomes. 8. g a: sister chromatids separate and move to opposite sides of the cell. the s a pulls them apart. this phase ends when the chromatids stop moving. 9. _ telophase: two nuclear envelopes begin reforming. chromatids relax, uncoil & are now chromatin. cytokinesis is occurring during telophase but it is not considered a part of mitosis because it does not involve the nucleus of the cell. in plant cells, a cell plate begins to form while a c__ f is visible in animal cells. 10. _ mitosis: division of a cell’s nucleus. occurs in this order: prophase, __, __, and telophase.

Explanation:

Step1: Recall cell - cycle knowledge

The interphase consists of G1, S and G2 phases. In the given diagram, interphase is labeled as A.

Step2: Identify cytokinesis stage

Cytokinesis results in two identical daughter cells. In the cell - cycle diagram, it is usually the last stage after mitosis. Let's assume it is I.

Step3: Locate G1 phase

The G1 phase is a growth phase that makes organelles and proteins for DNA replication and has a G1 checkpoint. It is part of interphase. Let's assume it is part of A (interphase).

Step4: Locate S phase

The S phase is where DNA is replicated. It is part of interphase. Let's assume it is part of A (interphase).

Step5: Recall G2 phase details

The G2 phase is a growth phase preparing for mitosis (M phase). It has a G2 checkpoint. D is given for this description.

Step6: Identify prophase

Prophase is characterized by chromatin condensation, nuclear - envelope breakdown, and centriole migration. Let's assume it is B.

Step7: Identify metaphase

In metaphase, sister chromatids line up along the metaphase plate and the spindle apparatus attaches at the centromere. Let's assume it is C.

Step8: Recall anaphase details

In anaphase, sister chromatids separate and are pulled apart by the spindle apparatus. G is given for this description. The words are Anaphase; spindle; apparatus.

Step9: Identify telophase

Telophase involves nuclear - envelope re - formation and chromatin relaxation. Cytokinesis occurs during telophase. Let's assume it is H. In animal cells, a cleavage furrow is visible.

Step10: Recall mitosis order

Mitosis occurs in the order of prophase, metaphase, anaphase, and telophase. The missing stages are metaphase and anaphase.

Answer:

1. Interphase
2. I; daughter
3. A
4. A
5. Mitosis
6. B
7. C; metaphase
8. Anaphase; spindle; apparatus
9. H; cleavage furrow
10. metaphase; anaphase