1How do you prepare a root tip for mitosis observation?
Cut 1 cm from a growing root tip.
2Why is the root tip boiled in hydrochloric acid?
To soften the tissue and break down cell walls.
3What is the purpose of staining root tips?
To make chromosomes easier to see under a microscope.
4How do you squash the root tip cells?
Press a cover slip firmly over the cells to spread them thinly.
5What stains are used for observing chromosomes?
Toluidine blue O, acetic orcein, or Feulgen stain.
6What is the first step in using a microscope?
Place the slide on the stage and select the lowest-powered objective lens.
7How do you focus a microscope?
Use the coarse adjustment knob first, then refine with the fine adjustment knob.
8What do you do if the image is unclear?
Switch to a higher-powered objective lens and refocus.
9Why should you write down the magnification used?
To calculate cell sizes and ensure accurate documentation.
10What is an eyepiece graticule?
A transparent ruler in the microscope’s eyepiece with divisions but no units.
11What is a stage micrometer?
A slide with an accurate scale to calibrate the eyepiece graticule.
12How do you find the value of one graticule division?
Divide the stage micrometer scale by the number of graticule divisions.
13How do you calculate the actual size of a cell?
Actual size = size of image ÷ magnification.
14What are artefacts in microscopy?
Visible features that are not part of the specimen, e.g., dust or air bubbles.
15Why are artefacts common in electron microscopy?
Specimen preparation has many steps, increasing artefacts.
16How can you distinguish artefacts from organelles?
Prepare specimens differently and compare the results.
17What is the formula for the mitotic index?
Mitotic index = (number of cells with visible chromosomes) ÷ (total number of cells observed).
18What does a high mitotic index suggest?
Active tissue growth, repair, or cancerous activity.
19What are the visible stages of mitosis?
Prophase, metaphase, anaphase, and telophase.
20Why is only the tip of the root used?
It has actively dividing cells where mitosis is occurring.