Research question:
How does the chromatin change throughout mitosis?
Hypothesis:
In prophase chromosomes will be seen inside the nucleus. In metaphase aligned chromosomes in the middle of the cell will be seen. Separate chromatids being pulled apart will be seen in anaphase. In early telophase two nuclei’s inside one cell will be seen.
Explanation of hypothesis:
In prophase the chromatin in nucleus condenses to form chromosomes. In metaphase the chromosomes are line up in the middle of the cell. In anaphase lined up chromosomes are split. The chromatids than are s by microtubules. In early telophase two nuclei’s can be seen before the cell wall forms and the nuclei splits.
Variables:
Dependent: quality and amount of details of an image obtained by looking through compound light microscope and the picture taken with a camera.
Independent: the way of presenting the specimen, type of specimen: onion root tips.
Fixed: illumination of stage of microscope, cleanness of microscope and slides, precision of observer
Uncontrolled variables: changes of environment, and uncontrolled changes of specimen within wet mount or prepared slides
Apparatus:
Compound light microscope
Camera
Onion
Jar
Gauze
Rubber band
5mL 6M HCl
2mL Feulgen reagent
5mL 45% acetic acid
250mL beaker
5mL of violet
Scalpel
2 Vials
Procedures:
1) Fill the jar with water. Cover it with a gauze and support with a rubber band. Place the onion on the gauze so that it gently touches the water.
2) Grow the onion for 2 weeks controlling the water level and the amount of light.
3) Using the scalpel cut off the onion root tips.
4) Place the root tips in a 100mL beaker filled with 5mL 6M HCl for 1 minute. Transfer the tissue into a vial containing 2mL Feulgen for 20 minutes. Place the roots in 5ml 45% acetic acid afterwards.
Preparing the specimen:
Place the root tip on a clean glass slide. Pure 1 drop of acetic acid on the specimen laid on the glass slide and another drop of violet. Cover it with a glass slide.
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE
Conclusion:
My experiment confirmed the hypothesis that the chromosomes could be seen inside the nucleus in. In metaphase aligned chromosomes could be seen in the middle of the cell, that separate chromatids being pulled apart will be seen in anaphase and that two nuclei’s inside one cell will be seen in early telophase.
Evaluation:
The experiment turned out right. Mitosis could be seen in all stages. The experiment could be improved by using a better camera rather than a low quality one from a cell phone.