Answer:
The correct order is dehydration, embed in wax, cut into sections, staining
Explanation:
There are certain proceedings needed to obtain stained sections of vegetable or animal tissues for their microscope observations.
These steps are:
- Obtention of the material: The tissue is cut to an adequate size.
- Fixation: When tissues are extracted from the organism, they suffer autolysis and putrefaction, so they need to be fixated in order to keep their cells in the best state possible. Fixation involves preserving the original morphological and molecular characteristics of the tissue. Fixation avoids autolysis, putrefaction, distortion, and retraction of cells and the tissue that could affect its volume or morphology.
- Dehydration. Once fixated, the fixator must be eliminated and the tissue is dehydrated by using a gradual series of solutions with alcohol in ascendant concentrations. Dehydration must be gradual to avoid tissue deformation.
- Inclusion. To obtain thin cuts that can be observed under the optic microscope, the tissues must be included in a consistent, firm substance, that might be either hydrophilic or hydrophobic. A hydrophobic medium is paraffin wax, that provides hardness and plasticity.
- Cut. The tissue included in wax must be cut in slides or sections thin enough to allow the diffusion and penetration of light. A microtome is used to perform these cuts. When using paraffine for tissue inclusion, the cuts are about 5 to 20 micrometers of thickness.
- Stain. Once the cuts are performed, paraffin wax must be eliminated. This can be done by using an organic solvent. Then the tissue must be stained. Hematoxylin and Eosin are the most common dyes. Animal tissues in general do not have any natural color, so they need to be stained to be observed.
Answer: Chlorophyll is a substance inside the chloroplasts which is used to absorb light from the sun in order to provide the plant with energy to photosynthesise
Explanation:
<span>Cell division has two checkpoints namely, G1 checkpoint and spindle assembly checkpoint. The checkpoint which determines if division has properly occurred is the G1 checkpoint. At this point, is a damage in the DNA is detected or the has not reach the optimum size, the cell is stopped in G1 and is not allowed to proceed to further process.</span>
Answer:
There is a great difference between light and scanning electron microscope. The source of illumination is light rays in light microscope while in scanning electron microscope electrons are the source of illumination.
The resolving and magnification power of scanning electron microscope is much greater than that of a light microscope. The magnifying power of a light microscope is 1000X and of electron microscope is 10,00,000X.
In light microscope image is seen through the eyepiece while in scanning electron microscope it is seen on a fluorescent screen. Even small specimens up to 0.1 micrometers can be seen by scanning electron microscope which is not possible to see by light microscope.
They are oxygen, carbon, hydrogen, and nitrogen.
