Answer:
The creation of the limbs is carried out by AER and ZVP. AER stands for apical ectodermal ridge and ZVP stands for polarising activity line.
Explanation:
- AER is responsible for the developmental progression in the distal to the anterior region and the ZVP is liable for the progressive advancement in the posterior to a backward region.
- AER and ZVP are interconnected on one another in the secretion of a sonic hedgehog, which eventually assists throughout the hox speech to promote the growth of the arm.
- The hypothesis that the new short-arm gene inhibits the effect of FGF (fibroblast growth factors) on AER can be tested and use a template of cultured cells.
- The AER may be disrupted in the model and the impact of the gene encoding on FGFs may be examined. If in the existence of a viral vector, the role of the FGFs is to trigger correct growth, then the hypothesis is incorrect, or else the hypothesis is right. The FGF8 is by far the most powerful of all as the result.
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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Answer:
Fungi can be divided into two broad groups, called ascomycetes and basidiomycetes, depending on how their sexual spores are formed.
<span>The most obvious change due to seasonal variation is the change from summer to winter. Some animals migrate to other parts of the world, such as migratory birds. Many animals in colder climates hibernate. In both cases, the absence of these animals leads to a gap in the ecosystem. In regions with highly seasonal rainfall, the low rainfall season can lead to low flows in rivers, and a reduction of certain habitats for some aquatic organisms, such as beaver or aquatic insects.</span>
