Why is onion good to observe mitosis?
- Potato – This is a stem, an underground storage stem called a tuber.
- Carrot – This is a modified tap root, for storage.
- Celery – Leaf; the part we eat is an enlarged petiole (the stem of the leaf).
- Broccoli tops — These are sometimes called florets, meaning flowers. ...
Why are onion root tips used for studying mitosis?
a) Onion root tip (and whitefish embryos) are used because these tissues are growing fast and will have lots of mitosis occurring. It is easy for us to find cells dividing here.
Is mitosis and meiosis the same thing?
The difference between Mitosis and Meiosis is quite apparent. They are two very different processes that have two different functions. Meiosis is required for genetic variation and continuity of all living organisms. Mitosis, on the other hand, is focused on the growth and developments of cells.
Why would onion root tip have many cells undergoing mitosis?
It is because of the meristematic cells that are situated in the tip of the roots that render the most desirable and suitable raw material to study the different stages of mitosis. Onion is a monocot plant. Monocotyledonous plants possess large chromosomes that are clearly visible. Hence, their root tips are used.
Where does mitosis occur in an onion root?
apical meristemOnions have larger chromosomes than most plants and stain dark. The chromosomes are easily observed through a compound light microscope. The cells pictured below are located in the apical meristem of the onion root. The apical meristem is an area of a plant where cell division takes place at a rapid rate.
Where is most of the mitosis happening in the root?
Root tip would be the place where the highest rate of mitosis is because this is where the tissues are continuously subject to damage.
In what phase were most of the cells in the onion root tip?
The most onion root sells were in the interphase stage.
Where does mitosis occur most frequently in plants?
The areas of plants where mitosis happens most rapidly are the stems, side branches and root tips.
Why does mitosis occur in onion root tip?
Why is onion root tip used to demonstrate mitosis in this experiment? It is because of the meristematic cells that are situated in the tip of the roots that render the most desirable and suitable raw material to study the different stages of mitosis. Onion is a monocot plant.
In what stage were most of the onion root tip cells in based on what you know about cell division What does this imply about the lifespan of a cell?
The cells cycle stage that most of the cells were in was interphase. To me, this implies that the cells in the onion root tips typically spend a good amount (if not all) of their life span in the interphase stage.
In what stage of the cell cycle does a typical onion root tip meristem cell spend most of its time explain your answer by utilizing your data?
The cells spend the majority of their time in interphase.
Which phase of the cell cycle is this onion cell in?
1. 1: Cells in an onion root in interphase and prophase. Cell A has a large, dark nucleolus surrounded by greyish material (chromatin) that is enclosed within the nuclear membrane. A cell wall makes a box around each cell and the plasma membrane would be located just inside this box, though we cannot easily see it.
Which section of the root has the most dividing cells?
The root apical meristem, or root apex, is a small region at the tip of a root in which all cells are capable of repeated division and from which all primary root tissues are derived.
What zone in the root produces new cells by mitosis?
The zone of cell division is closest to the root tip; it is made up of the actively dividing cells of the root meristem. The zone of elongation is where the newly formed cells increase in length, thereby lengthening the root.
Why is there more mitosis in roots than stem?
The root tip shows more cells undergoing mitosis because the root tip needs to grow more than the woody stem. Thus, the root tip cells divide more frequently.
Why is the rate of mitosis in plants highest in the root tips?
Cell Type & Location Skin cells, hair follicles and the cells lining our intestines (epithelial cells) all have high rates of mitosis as these tissues constantly need to be replaced. In plants growth occurs largely at the shoot and root tips. These cells have much higher rates of mitosis than the rest of the plant.
Why do onion root tips grow?
Because of the rapid rate at which onion root tips grow as a result of rapid cell division, it's possible to observe and identify the different stages of mitosis.
Why do onion roots divide?
As mentioned, onion root tip cells divide rapidly as the roots elongate to absorb water and various minerals from the soil. For this reason, it's possible to identify different stages of cell division by mitosis based on chromosomal distribution.
What is the process of mitosis?
Mitosis refers to a type of cell division (cell cycle) through which the cell (parent cell) produces two identical daughter cells. Unlike meiosis, which is also a type of cell division, mitosis results in the production of two diploid daughter cells. The two daughter cells contain the same number of chromosomes as the parent cell.
What happens to the sister chromatids in anaphase?
At the end of this stage (late anaphase), the sister chromatids completely separate and reach the opposite poles of the cell.
Why do chromosomes become more visible in metaphase?
During metaphase, chromosomes become more visible because of increased condensation as well as the fact that the nuclear envelope has disappeared.
What is the diagrammatic representation of an onion root tip cell during interphase?
Diagrammatic representation of an onion root tip cell during interphase. Credit: MicroscopeMaster.com. During interphase, also known as the resting stage, the chromatin is not tightly packed. This allows for DNA to be copied (replication) as the cell prepares for cell division.
What is the second stage of mitosis?
Prometaphase is the second stage of mitosis (it has also been referred to as late prophase). This stage is characterized by increased condensation of chromosomes as well as the breakdown of the nuclear envelope (nuclear membrane).
What is the interphase of mitosis?
Cell that are actively dividing but not yet in mitosis are said to be in interphase, during which time the DNA is copied and the cell is otherwise preparing for replication. Some root cells have ceased dividing and are only increasing in size, whereas others have reached their final, mature size and function, and are said to be in the GO stage.
Can you grow onions in a lab?
While actively growing onions are present in the lab for you to observe, you will be provided with roots that have been previously harvested and treated with a fixative to stabilize the cells. You will work in groups of two for this lab exercise.
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…