Cell Cycle AP Biology Lab

Cell Cycle AP Biology Lab

Step 1

Research Hypothesis

If both plant and animal cells undergo mitosis to grow, and we count the number of cells in each cycle across a sample of cells, then plant and animal cells will have proportionate amounts of cells in each cycle, meaning that plant and animal cells spend the same proportion of time in each stage.

Scientific Explanation

Research Question

Scientific Question

Scientific Concepts

Evidence From Data

Data and Observations

Step 2

The largest amount of cells were found to be in interphase.

Interphase is the longest portion of the cell cycle, including the Gap 1, Synthesis, and Gap 2 phases.

Do Plant and Animal Cells Spend the Same Proportion of Time in Each Stage of the Cell Cycle?

After Experimentation

Lower amounts of cells were found to be in a phase of mitosis.

Mitosis only takes up a small portion of the total cell cycle.

Cell Pictures

All eukaryotic cells undergo the same phases of mitosis, which only takes up a small portion of the cell cycle.

Both plant and animal cells had lower number of cells undergoing mitosis.

Animal Cells

Plant Cells

Cells found right above a dead layer of cells in the onion root tip samples underwent mitosis at higher rates.

Root tips undergo quick growth as they spread, but the cells at the root tips are actually dead.

Do Plant and Animal Cells Spend the Same Proportion of Time in Each Stage of the Cell Cycle?

Both plant and animal cells had roughly the same percentage of cells in each phase.

All eukaryotic cells go through the cell cycle, and mitosis is very similar in both plant and animal cells.

Claim

To Analyze the Data and Conclude

Data Table with Raw Values

Data Table with Formulas

Both animal and plant cells spend relatively the same amount of time in each phase of the cell cycle.

Scientific Explanation

Both animal and plant cells spend relatively the same amount of time in each phase of the cell cycle. It was noticed that the largest amount of cells were found to be in interphase, which was expected as interphase is the longest portion of the cell cycle. Lower amounts of cells were also to be found in the mitotic phases, which was due to the fact that mitosis only takes up a small portion of the cell cycle. Both plants and animal cells had lower number of cells going through mitosis since all eukaryotic cells undergo the same phases of mitosis. Cells found right above the dead layer of cells in the onion root tip samples underwent mitosis at higher rates. Since root tips grow quickly, mitosis must occur at higher rates in the tips of the roots behind the layers of dead cells. Additionally, since the cell cycle is very similar in both plant and animal cells, both cell types were observed to have very similar amounts of cells in each stage, relatively. Thus, it can be determined that both plants and animal cells spend the same amount of time proportionate to their lifespans in each phase of the cell cycle.

Observations

The proportions of plant and animal cells is relatively similar across all phases of mitosis, the largest difference being in prophase. Approximately 0.5% more animal cells were in prophase. Metaphase and anaphase had the exact same percentage for both plant and animal cells. Plant cells had 0.3% more cells in telophase and 0.1% more cells in interphase. Across both plant and animal cells, interphase was the overwhelmingly common phase, with both types being about 80% of the sample size. In the onion root tip, more cells underwent mitosis in the area just above the dead cells. Another observation is that there were about 700 more plant cells in our counts than animal cells, indicating that there are areas in plant cells that are potentially more suitable for mitosis, where in other locations, a G0 phase may be more common.