The most characteristic feature of clastic sedimentary rocks is "stratification".
<u>Answer:</u> Option A
<u>Explanation:</u>
"Stratification" is an essential characteristic of the sedimentary rocks take place in an igneous rock produced at the surface of the Earth naturally due to volcanic fragmental deposits and flows of lava. It defines the pattern in which sediment layers are layered over each other and may occur on a scale of hundreds of meters, even down to sub-millimeter.
It also results from variations in texture or composition during deposition. Delays in deposition may also permit for variations to the older deposits before coverage given by new sediments. This mechanism in sedimentary rocks change in both, the degree of prominence and in structure details.
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 answer is macrophages. They either actively invade these leukocytes or are phagocytosed, divide in the cells and cause lysis. The promastigotes that invade these leucocytes are transformed into amastigotes in the macrophages. These amastigotes continue attacking other healthy macrophages while others migrate to the mid gut.
The correct answer fro above statement is:
<h3> c. Half of all rainforest plants have been tested for their medicinal properties.</h3><h3>Explanation:</h3>
Twenty-five percent of the fresh components in cancer medications are particularly rainforest plants.Rainforests are essential because they serve control global climate trims and rain. Water that disappears from trees comes in other regions as rain.Twenty-five percent of Western pharmaceuticals are obtained from rainforest components. But since only a minute portion of rainforest organisms have been investigated, as the rainforest species escape so do possible remedies and therapies for life-threatening disorders.
