Answer:
I think it's chromosome.
Explanation:
A chromosome looks roughly like an X, but it does not maintain it's form. IT floats around and stuff. That's why I think it's chromosome.
The Sahel. The Sahel is a region of sub-Saharan Africa and it is also a zone of ecological transition between the Sahara to the north and the wetter savannas to the south. Sahel belt or Sahel is a tropical savanna ecoregion in Africa. Africa is the second largest continent. It has 54 sovereign countries.
Answer:
The correct answer is D) short-lived plasma cells that secrete antibodies for the antigen
Explanation:
Each B lymphocyte has an antigen receptor (BCR: B cell receptor), a surface immunoglobulin (IgM or IgD), that binds to specific domains of the antigen called antigenic determinants or epitopes. Only B lymphocytes with a high antibody affinity for the antigen, and which are capable of processing and presenting it, will be positively selected. In this contact between the two cells, an exchange of chemical signals takes place that leads to the activation, clonal proliferation and differentiation of B cells into two sister subclones: one of antibody-secreting plasma cells, and the other of memory primed B cells. Therefore, only these last positively selected B lymphocytes will survive, proliferate and differentiate into plasma cells, synthesizing and secreting antibodies of a single isotypic class, with a unique specificity and high affinity, improving the ability to adhere to the antigen and, thus , neutralize and destroy pathogens.
Answer:
Fungal
Explanation: took the test!! :)
