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:
48 amino acids
Explanation:
The wild type gene codes for a protein with 100 amino acids. One amino acid is encoded by one triplet code of the gene. This means that the wild type gene has a total 100 triplets or 300 nucleotides to code for a protein of 100 amino acid. Mutation in this protein has introduced the code "UAA" at the 49th codon. The code "UAA" is a stop codon. Therefore, the mRNA transcribed from the mutant allele would code for a protein having 48 amino acids as the protein synthesis will be stopped once the stop codon at the 49th position is read.
I would say the last one. Yes, the coral reef in the south is being threaten but, it’s not the only one. Many other reefs are being threatened. Why? To find the problem to this reef you need to find the problems of other reefs and compare the data. Which ever the most problem cause you get rid of that first.
Answer:
A society is choosing to replace its nuclear power plants with more sustainable geothermal power plants. Which of the following is an advantage to switching to geothermal power?
A. It can contaminate groundwater.
B. It uses a renewable resource.
C. It consumes a radioactive material.
D. It produces more hazardous waste.
Explanation:
Explanation:
Gravitational potential energy is the energy of body due to its position in the gravitational field.
Whereas chemical potential energy is the energy within the chemical bonds of a substance.
For example, when we eat an apple then we get energy in our body so, it is the chemical potential energy stored in the apple.
Items sorted on the bases of gravitational potential energy and chemical potential energy are as follows.
Gravitational potential energy:
- a ball thrown up in the air.
- a stone rolling downhill.
- water stored in an overhead tank.
Chemical potential energy:
- liquid petroleum gasoline used in cars.
- firecrackers that people set off.
