What are onion root tip visible parts?
Study Of Mitosis In Onion Root Tip Cells
- Aim Of The Experiment. To study and demonstrate mitosis by preparing the mount of an onion root tip cells.
- Theory Of The Experiment. For entities to mature, grow, maintain tissues, repair and synthesize new cells, cell division is required.
- Materials Required
- Procedure Of The Experiment. ...
- Observations and Conclusion. ...
- Viva Questions. ...
What is the mitotic index for the onion root tip?
Mitosis in Onion Root Tip . Mitotic Index . The percentage of cells undergoing mitosis or it is defined as the ratio of no. of cells in the dividing phase to the total number of cells observed. This will help to identify the region of most mitotic activities. Mitotic index helps us to quantify the cell division.
What is onion root tip?
- 70 percent alcohol
- Aceto-alcohol
- Blade
- Forceps
- Glass slides
- Water
- Glycerin
- Stain - Aceto-carmine or Aceto-orcein
- Hydrochloric acid solution (1N HCL)
- Onion with freshly grown roots
What type of root is found in onion?
Onion is a monocot plant. Monocotyledonous plants possess large chromosomes that are clearly visible. Hence, their root tips are used. The period of time taken for mitosis varies as it is dependent on the cell type and type of species. Is mitosis influenced by any factor?
How long does an onion root tip cell spend in interphase?
Step 2: Calculate the time an onion root tip cell spends in part of the cell cycle. The cell cycle for onion root tips takes about 720 minutes (12 hours).
How long do onion cells spend in mitosis?
TOTAL Number of Cells Remember that mitosis in an onion root tip normally takes about 80 minutes at room temperature.
What percent of time do cells in the onion root tip spend in mitosis?
Because 42 cells of the 100 cells are in one of the phases of mitosis, the mitotic index for this population of onion root tip cells is 42%.
How much time do cells spend in interphase?
In sum, then, interphase generally takes between 18 and 20 hours. Mitosis, during which the cell makes preparations for and completes cell division only takes about 2 hours.
How much time is spent in each phase of mitosis?
From the frequency of mitotic phases, defined as indicated in the preceding article (El-Alfy & Leblond, 1987) and corrected for the probability of their occurrence, it was estimated that prophase lasted 4.8 hr; metaphase, 0.2 hr; anaphase, 0.06 hr and telophase, 3.3 hr, while the interphase lasted 5.4 hr.
How do you find the duration of interphase?
(P+M+A+T) — the sum of all cells in phase as prophase, metaphase, anaphase and telophase, respectively; N — total number of cells. From the cell cycle, 1.2% is mitotic and the rest will obviously be interphase. So, 1.2% is 30 minutes, so 100% (length of total cell cyle) is 2500 minutes (42hours).
Why do onion root cells spend most time in interphase?
Cells in this phase generate proteins, growing to somewhat double their size. To sum it up, the cell grows, develops, prepares itself for cell division, replicates its chromosomes, etc during this phase, thus a cell spends most of its time in this stage.
What percentage of the cell cycle were the onion root cells in interphase?
Approximately 60% of the cells were in interphase. The next most common stage observed was prophase, and 35% of cells were in this phase.
Why do onion root tips spend the most time in interphase?
Based on this data, I can see that the onion root spent the majority of the time in Interphase because it is the longest stage. Prophase it the second longest stage. The remaining stages would vary. The different cells have differing numbers for the other three stages.
Which cells spend the most time in interphase?
2 Answers. Majority of eukaryotic cells spend most of their time in interphase.
Which is the longest phase of interphase?
S Phase (Synthesis of DNA) The synthesis phase of interphase takes the longest because of the complexity of the genetic material being duplicated.
What phase do cells spend the shortest time in?
MechanismThe mitotic phase is usually the shortest part of any cell cycle. ... Throughout mitosis, certain checkpoints are essential to the continuation of the process. ... There are three main checkpoints in mitosis, and those include the G1/S checkpoint, G2/M, and metaphase/ anaphase checkpoint.More items...•
Overview
Experiment
- For this section, the experiment will be divided into two main parts. These include: 1. Growing onion root tips 2. Sample preparation
Requirements
- Uncut onions
- Clear glass or plastic jars
- Clean water
Procedure
- Pour clean water into the clean (and clear) glass/plastic jars - about three-quarters full.
- Carefully place the onion bulbs in the glass/plastic jars so that only the lower surface of the onion comes in contact with the water.
- In a case where the onions are too small, they can be supported using toothpick/splints.
- Let the onions rest on water for 3-4 days - only the lower surface (base from which roots eme…
- Pour clean water into the clean (and clear) glass/plastic jars - about three-quarters full.
- Carefully place the onion bulbs in the glass/plastic jars so that only the lower surface of the onion comes in contact with the water.
- In a case where the onions are too small, they can be supported using toothpick/splints.
- Let the onions rest on water for 3-4 days - only the lower surface (base from which roots emerge) should be in contact with water.
Under 10X Magnification
- Under 10X magnification, students will be able to observe several single layers of cells. Depending on how well the slide was prepared, the cells are spread out without any overlapping or with very little overlapping. *Generally, a row of cells (single layer) may consist of between 2 and 5 cells. The following is a diagrammatic representation of onion root tip cells under 10X magnification:
Higher Magnification
- Under high magnification (100X-500X), it becomes possible to identify cells at different stages of mitosis. These include: Interphase While this is not necessarily one of the main stages of mitosis, cells in this state can easily be identified by their prominent nucleoli. Diagrammatic representation of an onion root tip cell during interphase: During interphase, also known as the resting stage, th…
Cytokinesis
- Cytokinesis refers to the process through which the cytoplasm separates as the cell divides into two identical daughter cells. Unlike animal cells, plant cells have a rigid cell wall that prevents the cell from easily pinching apart to form two identical daughter cells. For this reason, the process of cytokinesis is different in these cells (plant cells). During late telophase and early cytokinesis, ca…
References
- Cooper GM. (2000). The Cell: A Molecular Approach. 2nd edition. Donald, B. and Richard, J. (2018). Cell Division. An Atlas of Comparative Vertebrate Histology. Lian, Y. and Chirop, M. (2016). Functional Cell Biology. Encyclopedia of Cell Biology. Lodish H, Berk A, and Zipursky SL, et al. (2000). Microtubule Dynamics and Motor Proteins during Mitosis: Molecular Cell Biology. 4th ed…