Introduction
Good day students!
In this WebQuest you’ll learn about mitosis which is our topic of the day. I believe you have learnt about cell division in your previous grades, mitosis is the division of cells. Please watch the following video where I’ll be explaining more about mitosis and it’s stages.
Task
Date: 28 August 2021
Assessment 2
Marks: 25
Watch the video bellow and answer the following questions.
Question 1.
- How many stages does mitosis consists of? (2)
- Which stage of mitosis do chromosomes line up in the centre of the equator? (2)
- What is the name of the structure that holds chromatids together? (2)
- How many daughter cells are formed in the last stage of mitosis? (2)
- What is responsible for the formation of spindle during mitosis? (2)
Question 2.
Match column A to a suitable explanation in column B. (10)
| Column A | Column B |
| 1. Cell cycle | A. The period between cell division during which the cell grows and prepare to divide. |
| 2. Replication | B. DNA molecules in the cell nucleus make copies of themselves |
| 3. Duplication | C. Series of processes that take take place in a cell between one cell division and the next. |
| 4. Interphase | D. Division of the cell nucleus |
| 5. Cytokinesis | E. When copies of the chromosomes are formed |
Question 3
1. Name and explain the process of the last stage of mitosis (5)
Total= 25 marks
Process
Please watch the following video in order to understand the purpose of mitosis, it’s stages and the process of each stage. This video covers every important information of mitosis that you’ll need to know. After the video you’ll find notes explaining morel further about mitosis.
What is mitosis?
Mitosis is a process where a single cell divides into two identical daughter cells (cell division).
- During mitosis one cell? divides once to form two identical cells.
- The major purpose of mitosis is for growth and to replace worn out cells.
- If not corrected in time, mistakes made during mitosis can result in changes in the DNA? that can potentially lead to genetic disorders?.
Mitosis is divided into five phases:
1. Interphase:
- The DNA in the cell is copied in preparation for cell division, this results in two identical full sets of chromosomes?.
- Outside of the nucleus? are two centrosomes, each containing a pair of centrioles, these structures are critical for the process of cell division.
- During interphase, microtubules extend from these centrosomes.
2. Prophase:
- The chromosomes condense into X-shaped structures that can be easily seen under a microscope.
- Each chromosome is composed of two sister chromatids, containing identical genetic information.
- The chromosomes pair up so that both copies of chromosome 1 are together, both copies of chromosome 2 are together, and so on.
- At the end of prophase the membrane around the nucleus in the cell dissolves away releasing the chromosomes.
- The mitotic spindle, consisting of the microtubules and other proteins, extends across the cell between the centrioles as they move to opposite poles of the cell.
3. Metaphase:
- The chromosomes line up neatly end-to-end along the centre (equator) of the cell.
- The centrioles are now at opposite poles of the cell with the mitotic spindle fibres extending from them.
- The mitotic spindle fibres attach to each of the sister chromatids.
4. Anaphase:
- The sister chromatids are then pulled apart by the mitotic spindle which pulls one chromatid to one pole and the other chromatid to the opposite pole.
5. Telophase:
- At each pole of the cell a full set of chromosomes gather together.
- A membrane forms around each set of chromosomes to create two new nuclei.
- The single cell then pinches in the middle to form two separate daughter cells each containing a full set of chromosomes within a nucleus. This process is known as cytokinesis.
Evaluation
| Question | Mark |
|
Question 1
|
10 Each question consists 2 marks, simply write the correct answer in each question. |
|
Question 2
|
10 Choose the correct explanation and only write the correct letter. |
|
Question 3
|
5 Write a short essay of explanation. |
Conclusion
Please watch these videos and study the notes provided until you understand the processes of each stage of mitosis as to prepare yourselves for the test you’ll be writing on our next class.
Credits
Teacher Page
WebQuest is a very valuable and effective tool for teaching on both teachers and learners. Learners could get more information through it and study at their own pace.
For more information contact me: amishy1408@gmail.com
Amanda Silevu
Student number: 219087393