Mitosis

Open Ended

How does your body make new cells?

Open Ended

Why isn’t the new skin green, scaly, or different when your skin heals?

• First part of Interphase

• Cell is growing in size.

• Cell makes proteins and organelles it will need later.

• Cell does its normal job (ex: skin cells make skin proteins).

• Cell prepares for DNA replication.

🔬 G1 Phase (Gap 1)

• DNA is copied (replicated) so each chromosome makes an identical sister chromatid.

• After S phase, the cell has double the DNA, but the same number of chromosomes (just duplicated).

• This ensures that when the cell divides, each daughter cell gets a full set of instructions.

🧬 S Phase (Synthesis)

• Cell keeps growing a bit more.

• Cell makes spindle fibers and other proteins needed for division.

• DNA is double checked for mistakes (quality control).

• The cell gets fully ready to enter mitosis.

🔬 G2 Phase (Gap 2)

Multiple Choice

Explain how mitosis ensures that daughter cells are genetically identical to the parent cell.

• Mitosis ensures daughter cells are genetically identical to the parent cell by replicating DNA and equally distributing identical chromosomes during cell division.
• Mitosis creates daughter cells with half the DNA of the parent cell.
• Mitosis results in daughter cells that are genetically different from the parent cell.
• Mitosis involves the mixing of DNA from two parent cells.

Multiple Choice

The process in which the cytoplasm splits into two cells at the end of the cell cycle is called ___.

• mitosis
• cytokinesis
• cell division
• meiosis

Multiple Choice

Which phase of the cell cycle involves DNA replication?

• G1 Phase

• S Phase

• G2 Phase

• Mitosis

• Chromosomes condense (get thick and visible).

• The nuclear envelope breaks down.

• Spindle fibers start forming from centrioles.

  (Like packing up your stuff into boxes before moving — DNA (which was loose) gets neatly packed so it can be moved safely.)

🌟 Prophase

• Chromosomes line up in the middle of the cell (equator).

• Spindle fibers attach to the centromeres.

(Like lining up kids in the middle of the gym before splitting into two teams.)

🌟 Metaphase

Multiple Choice

Describe the main events that occur during prophase and metaphase of mitosis.

• Spindle fibers detach from the centromeres during prophase.
• The nuclear envelope reforms and chromosomes decondense in metaphase.
• Chromosomes are replicated and separated during prophase.
• During prophase, chromosomes condense, the nuclear envelope breaks down, and the spindle apparatus forms. In metaphase, chromosomes align at the metaphase plate, and spindle fibers attach to their centromeres.

• Sister chromatids are pulled apart to opposite sides of the cell.

  • Each chromatid is now considered a full chromosome.

🌟 Anaphase

🌟 Telophase

​Chromosomes uncoil (DNA untangling). Nuclear envelopes reform around each set of chromosomes. The cell now has two nuclei.
Like setting up two new houses after the move each set of boxes (chromosomes) gets its own house (nucleus).

Multiple Choice

During which phase of mitosis do sister chromatids separate and move toward opposite poles of the cell?

• Prophase

• Metaphase

• Anaphase

• Telophase

Multiple Choice

Which of the following events occur during telophase?

• Chromosomes condense and become visible

• Nuclear membranes reform around chromosomes

• Spindle fibers attach to centromeres

• Sister chromatids are pulled apart

Multiple Choice

What happens to the cytoplasm during cytokinesis?

• It divides

• It disappears

• It merges with the nucleus

• It forms new organelles

🌟 Cytokinesis (not technically mitosis but happens after Telophase)

• Cytoplasm splits → two daughter cells.

• Each daughter cell is diploid and genetically identical to the parent cell.

Like dividing one classroom into two full classrooms, each with the same supplies and rules.

Multiple Choice

After mitosis, what is the chromosome number and genetic relationship of the daughter cells compared to the parent cell?

• Diploid (2n), genetically identical

• Haploid (n), genetically different

• Diploid (2n), genetically different

• Haploid (n), genetically identical

Multiple Choice

In which phase is DNA copied

• G1 phase
• M phase
• S phase
• G2 phase

Multiple Choice

Which stage lines up chromosomes in the middle?

• Metaphase

• Telophase
• Prophase
• Cytokenisis

Multiple Choice

Why are daughter cells genetically identical?

• Daughter cells are genetically identical due to mitosis.
• Daughter cells are genetically identical due to meiosis.
• Daughter cells are genetically identical because of genetic recombination.
• Daughter cells are genetically identical due to environmental factors.

Open Ended

If your skin cells didnt divide by mitosis, what might happen when your get a cut?

Open Ended

Explain how mitosis ensures that daughter cells are genetically identical to the parent cell. Use the terms diploid and chromosome in your explanation.

Multiple Choice

Which process is responsible for making new skin cells that look the same as the old skin?

• Mitosis

• Photosynthesis

• Meiosis

• Fermentation

Open Ended

Summarize what you learned today about how your body makes new cells. Why is this process important for your health?