In order to observe a specimen under 4X objective lens, the following procedures must be observed:
- Set up the microscope ensuring that the lens have been adequately cleaned and the light source is working
- Mount the object on a slide and place the slide on the stage of a clean microscope.
- Switch the revolving nose piece to ensure that the 4X objective is in position
- Switch on the light source
- Bring the object into focus by using coarse and fine adjustment knobs.
- Ensure that the image of the object is centered on the stage.
In order to observe the same specimen under the 100X objective:
- Switch the revolving nose piece to fix the 100x objective in place.
- Only use the fine adjustment knob to bring the image into focus
- If the image will not resolve properly, a few drops of immersion oil may be applied to the slide to improve resolution.
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Some activated b cells will move to the follicles where, with the aid of follicular t helper cells in the spleen and lymph nodes, they continue to differentiate.
<h3>B-cell differentiation: </h3>
In reaction to the antigens, these cells develop in the bone marrow and create antibodies. Humoral reaction involves B lymphocytes. B cells create plasma cells and memory B cells as soon as they come into contact with the antigens.
In the spleen and lymph nodes, B-cells develop into plasma cells. An immunoglobulin receptor on each B-cell can bind to a single, distinct, unprocessed antigen. After being exposed to an antigen, B cells release interleukins to become active.
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Answer:
c and b
Explanation:
cause I believe that because of the populations and polutions that is cause of humans we are now lack of protective shield and green gases within our atmosphere
The reason as to why fungi fossils seem so rare is that they are usually microscopic and often difficult or impossible to identify.
Not much information on fungi fossils has been documented. This could be because fungi fruiting bodies consist of soft, fleshy and easily degradable tissues which due to their poor integrity do not keep or preserve as well as animal tissue.
Even when available, it takes a trained eye to recognize fungal fossils. Not many people have the training and expertise to recognize the fossils.
Answer:
The nektonic organisms are those marine organisms that are found in almost every depth. These can move freely from one place to another in the ocean body due to its ability to swim. For example, Turtles, sharks, Fishes, and dolphins.
The planktonic organisms are passive swimmers, as they can move along with the ocean currents and are mostly found in the upper portion of the ocean body. For example, Diatoms and Rotifers.
The benthos is the bottom-dwelling organisms that cannot swim. For example, Bivalves, Corals and Sponges.
The nektonic organisms are different from the planktons and the benthos because the nektons can easily swim. They are constructed with such body parts that allow them to swim and migrate from one region to another region within the ocean water body. Whereas the planktons and the benthos cannot migrate easily and are considered as sessile organisms.
