Explain the difference between staining and not staining your specimens. Suggest why methylene blue was used to stain the check cells while iodine solution was used to stain the potato and onion...

  1. Explain the difference between staining and not staining your specimens.

  2. Suggest why methylene blue was used to stain the check cells while iodine solution was used to stain the potato and onion epidermal cell.

  3. Describe the difference between a light and electron microscope.

Asked on by yoshinni

3 Answers | Add Yours

sciftw's profile pic

sciftw | High School Teacher | (Level 1) Educator Emeritus

Posted on

You have three questions listed here.  Enotes' policy is that each question gets posted separately.  I'll answer part 3. 

A light microscope uses visible light to illuminate whatever object or specimen that an observer has placed on the microscope stage.  The light source could be sunlight or ambient room light.  If that is the case, the microscope will use a mirror that the user angles to specific orientations to best light the object.  Other light microscopes will use their own light bulb under the stage that shines up.  A diaphragm will be used to adjust the amount of light. 

An electron microscope uses a beam of electrons to magnify and resolve an image of a specimen.  Electron microscopes have much higher magnification powers than light microscopes as well as better resolving power.  A light microscope is capable of viewing something as small as bacteria, but not much smaller.  Conversely, an electron microscope can be used to view things on the nano scale.  Atoms for example.  Of course all of that magnification power comes with a much higher price than a typical light optical microscope.  

gsarora17's profile pic

gsarora17 | (Level 2) Associate Educator

Posted on

1. Staining is useful to highlight various structural features of the organism and  increases visualization of specific components within a cell. Without stains, cells appear almost transparent under a microscope.  Cell staining can also be used to highlight processes, such as the stages in cell division.

2. Methylene blue binds to DNA, so when we stain a cell with methylene blue, it allows us to see the nucleus of that cell. Iodine stains starch present in the onion cell, so staining a plant cell with iodine allows us to see the cell wall, chloroplasts and amyloplasts (starch storage vacuoles present in certain types of plant cells). 

Sources:
gabscho's profile pic

gabscho | eNotes Newbie

Posted on

  1. Explain the difference between staining and not staining your specimens.

        While staining is not always necessary to view specimens under a microscope it can allow you to view the internal structures of a cell better. When a stain is absorbed by a specimen it outlines different parts of it allowing you to better observe under the microscope.

2. Suggest why methylene blue was used to stain the check cells while iodine solution was used to stain the potato and onion epidermal cell.

       Methelyne blue is better suited for animal cells as it adheres better to the structures of the cell. Iodine is better suited for the potato, being a plant cell, because it contains more starch and can adhere to that. 

3. Describe the difference between a light and electron microscope

      The main difference is how specimens are viewed in each microscope. Light microscopes use light to view and electron microscopes use beams of electrons. Other difference include a light microscope being smaller and less expensive. Electron microscopes tend to have higher resolution and magnification. 

We’ve answered 318,917 questions. We can answer yours, too.

Ask a question