Cell Invesitgations in topic 2

Title: Cell Growth (pp.130 - 131 for stages of mitosis)

Aim: To determine whether root cell growth occurs at the top or the tip of the root.


DESIGN of investigation

(complete/2; partial/1; not done appropriately or at all/0)

Aspect 1. Research question
:
Are more cells in mitosis or interphase at the top of the root or at the tip of the root?
Variables:
Independent (conditions)
top and tip of root
Dependent (results) number of cell in mitosis and in interphase at top and tip of root
Control (constant) keep the garlic bulbs in the same conditions so that the tops and tips of the roots are exposed to the same water and temperature.
When counting, size of root tip and root top area is the same
measure size of cells you are counting

Theory. Since roots grow through mitosis, more cells in mitosis should be found where the most growth is occurring. Root growth can also occur when cells elongate ( grow larger).....

Aspect 3 Method for collection of data:
Garlic clove, 2 tooth picks, boiling tube (large testtube)

Per lab table: Fill test tube with water. Submerge the apex of a garlic clove 1 cm into the water of the test tube. Keep the rest of the garlic clove above the water by inserting two tooth picks into the clove and balance across the top of the test tube. Leave undisturbed in a warm place for 48 hours.
Per student: Choose a root from your table's garlic clove.

Follow directions from Robert's Biology student's manual: p 221, steps 1 - 9. Note that the stain will be already prepared for you and that each stage of mitosis does not need to be differentiated for this lab. You need to differentiate mitosis and intephase, as stated below.
To record data:
Count the cells in mitosis and those in interphase for the root top and the root tip
Measure the size of three cells in the root top and in the root tip

Aspect 2 Method for controlling the variables
The garlic bulb is placed at the top of a boiling test tube filled with water so that the bottom of the bulb is submerged 1 cm. This ensures that the root top and root tip will be both exposed to surrounding water. Water will be added if the level drops. The water temperature is the same throughout since the test tubes are all in the same environment.


DATA Collection and Processing

(complete/2; partial/1; Not done appropriately or at all/0

Aspect 1:
- Qualitative record
Diagram a section of the plant tip or root and show how you identified mitosis or interphase

- Quantitative record . Don't forget to include units and uncertainties where relaevant; for example, is each cell clearly distinguishable between mitosis or interphase?
1. Record quantitative count of cells in mitosis and cells in interphase for top of root and tip of root
2. Repeat each count 3 times in order to esatablish quantitative uncertainty.
3. Record data from other students so you have 3 data sets
4. Record the sizes of 3 cells from the top and from the tip of the root

Aspect 2: Processing data
5. Calculate the uncertainty for your data by +/-
6.. Calculate the mean of the 3 data sets
7. Calculate the mean of each of your 3 cell sizes
8. Graph the mean values for root tip and for root tip
Error and uncertainties
7. Include relevant error and uncertainty in both


Conclusion and Evaluation

(c/2; p/1; n/0)
Answer the research question Type in the content of your new page here.