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.
viruses are tiny bundles of genetic material which is carried in a viral coat.
<u>Explanation:</u>
- The virus is generally a parasite that needs a host to become active and to reproduce. It cannot reproduce without the host.
- The tiny bundle consists of genetic material and protein. The virus consists of capsid and nucleic acid. This capsid is said to be the protein coat.
- This capsid consists of either RNA or DNA. virus replicate themself within the host body by using its genetic material along with the mechanism of the host.
- Thus after replicating the virus need to get out of host cell, It is performed by two types budding or lysis( bursting the host cell ).
Answer:
all of the above
Explanation:
Epigenetic alterations are modifications of the genome transmitted during cell division, which do not involve changes in the DNA sequence, are hereditary and are capable of modifying gene expression. In addition, they are temporary modifications that allow DNA to be transcribed and have the ability to move histones to open or close a chromosomal region. There are three main mechanisms of epigenetic alterations: DNA methylation, histone modifications and genomic imprinting.
Answer:
A, C, and D *maybe B but im not sure abt it*
Explanation:
