The answer requires looking at the meaning of the words 'theory' and 'law'. The formal definition of a theory is that it is a comprehensive explanation of a observed phenomenon supported by a lot of evidence. Law is a fact that is bound to be true in nature, example Newton's second law. However, a theory is subjected to continuous refinements based on the several new findings that happen with time. These refinements make the theory appear incomplete. As with the theory of evolution, a lot of research work is being put to understand the complex phenomenon of genetic inheritance of traits of behaviour. Unless there are evidences from nature for all the aspects of evolution in theory, it'll remain a theory and not become a law.
Answer is A) Yes, if scientists decide that enough evidence supports the theory.
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.
The right answer for the question that is being asked and shown above is that: "-an extrusive igneous rock." Darby finds a rock in her backyard. It has large crystals. She has found <span>-an extrusive igneous rock</span>
Hii and says he will not have any other plans to because he’s going up to north and north west of west
Answer:
D. They form an ionic compound.
Explanation:
The bonds which are produced between a metal ion and a non-metal ion are termed as ionic bonds.
