Later discoveries proved that cells are the building blocks for all living things, from microscopic bacteria to human beings. Although cells can take on innumerable shapes and functions within an organism, they all perform the basic roles of energy absorption and production, cellular maintenance and reproduction. Without cells, life cannot exist — albeit viruses, which lack cellular structure, imitate life by invading host cells to replicate.
Moreover, to avoid breaking the slide and damage to the microscope objective lenses during observation, it is important that the optical tube be lowered to the point that the objective lens is as close to the slide as possible.
This should be done starting with low power while looking from the side of the microscope rather than through the eye piece. From this point, it becomes easier to focus for clarity without any accidents.
Add a drop of water at the center of the microscopic slide Having pulled of a thin membrane from the onion layer, lay it at the center of the microscopic slide the drop of water will help flatten the membrane Add a drop of iodine solution on the onion membrane or methylene blue Gently lay a microscopic cover slip on the membrane and press it down gently using a needle to remove air bubbles.
Adjust focus for clarity to observe. Students can make another slide without adding the stain to see the difference between a stained slide and a non-stained slide.
Observations Clearly visible distinct cell walls surrounding the cells, Dark stained nucleus, Large vacuoles at the center, Small granules may be observed inside the cells within the cytoplasm The layers of an onion contain simple sugars carbohydrates some of which are stored as starch starch granules.
Given that iodine tends to bind to starch, it stains the starch granules when the two come in to contact making them visible. Although onions may not have as much starch as potato and other plants, the stain iodine allows for the little starch molecules to be visible under the microscope.
Although onions are plants, students will not see any chloroplasts in their slides. This is because of the fact that the chloroplast necessary for photosynthesis is largely present in the leafy part of the onion, which is exposed to the sun and absent in the bulb which is below ground and away from sunlight.
Unlike animal cells, students will also notice that the plant cells have a more regular shape. This is because they have a cell wall made up of cellulose which maintains its shape. Students have the opportunity to experiment and observe the onion membrane with different stains methylene blue and iodine and without the stain and observe the differences.ASSIGNMENT - Why is a cell microscopic?By Lachlan BryantThis research assignment will discuss why cells are usually microscopic in size, given that they need to be able to exchange material with their surrounding timberdesignmag.com cell is highly organise 5/5(4).
Report: Plant and Microscopic Stem Structure Essay; Report: Plant and Microscopic Stem Structure Essay. Words Apr 5th, 3 Pages. Show More. Edward R. Murrow Science Report Stem cell research is a very controversial, yet promising study.
“Stem cells are like little kids who, when they grow up, can enter a variety of professions. A. Essay on the Types of Cells Essay on Compartmentalization for Cellular Life Essay on Cell— An Open System Essay on the Shapes of Cells Essay on the Functions of Cell Parts ; Essay # 1.
Definition of Cell. Mar 27, · Why are cells usually microscopic in size? Given that cells need to be able to obtain their requirements from the surrounding environment and remove waste to the surrounding environment, suggest why cells are usually microscopic in size?Status: Resolved.
Why are cells so small? As Mendel describes in this story, cells are so small they cannot normally be seen with the naked eye.
There are also a lot of cells in the average organism, a fact that astonished their discoverer, Robert Hooke, who calculated from his observations of cork cells that there must be over a billion cells in one "cubick inch", a . What are some examples of the microscopic nature of cells?
Why is the microscope important to medical laboratory technology? What is the purpose of .