The thymus is the only lymphoid organ that does not D. fight the antigens directly.
- The thymus, bone marrow, spleen,lymph nodes, a network of lymphoid tissue along secretory surface (MALT), and the skin which performs the immune functions are known as lymphoid organs.
- On the basis of its role, lymphoid organ are classified into primary and secondary lymphoid organ.
- The lymphocytes from bone marrow are transformed into specialised T cells in the thymus. In this way thymus helps to improve the immune system
- T cells produced in the thymus is travels through the blood stream to lymphnodes and other parts of the body to fight against the antigen.
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Any form of precipitation, including rain, snow, hail, fog, or dew, that is high in acid pollutants, especially sulfuric and nitric acid. Acid precipitation has a pH of less than 5.6 (the normal acidity of unpolluted atmospheric water) and is often less than pH 5.0.
Air pollution can kill trees and can cause chronic disease
Criteria pollutants are simply a list of pollutants created by the EPA, designed to include the 6 most common air pollutants.
B) Carbon dioxide
CO2 is not on the EPA list.
<span>sporophytes
</span><span>A sporophyte produces spores therefore those plants that have spores is called sporophyte. A sporophyte is a type of a diploid organism so, which means that meiosis must occur in order to be able to produce haploid cells containing half number of chromosomes. Meiosis in sporophyte occurs in an area called sporangia. The spores that are being created inside sporangia shall be release into the air. Mitosis is expected to take place on a single haploid spore in order to be a multicellular gametophyte.</span>
Answer:
The correct answer would be the third option.
One of the hypotheses regarding the origin of life is "organic molecules from outer space".
Under this concept, it is believed that organic compounds might have come on earth through meteorites. Then these organic compounds were used as the precursors of the living cells.
Certain pieces of evidence are also found to support this concept.
For example, scientists have experimentally proved that conditions like low temperature and high UV radiations (similar conditions as exist in outer space) can result in the production of organic molecules from simple chemical precursors as present in space.
In addition, some organic compounds have also been found in space or other star systems.
