When focusing a specimen you should always start with the SCANNING objective. Scanning objective is used to put the object you want to examine in focus. After proper focusing on the object, you can now switch to power objective.
Answer:
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Proteins even make up most of your hair. ... While a structure such as a nucleus is only found in eukaryotes, every cell needs ribosomes to manufacture proteins. Since there are no membrane-bound organelles in prokaryotes, the ribosomes float free in the cytosol. Ribosomes are found in many places around a eukaryotic cell.</h2>
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<em>This isn't my answer, BUT, you can read more about the prokaryotic cells and their functions, and what they're made up of here at this website: </em>
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Answer:
According to Dr. Ray Schiling (member of the American Academy of Anti-aging medicine) about 1.5 million people suffer from peanut allergies. The seeds of peanut (<em>Arachis hypogea</em>) contain an array of allergens that can induce the production of IgE specific antibodies predisposed individuals. Ara1 and Ara2 are most common seed storage protein that cause allergy. Other allergen proteins such as Ara3 to Ara 17 have also been identified that cause allergy.
Entry of peanut allergen into body
When peanut allergens enter the body of an individuals it leads to development of different symptoms like itchy skin, tingling sensation, nausea, runny nose and anaphylaxis.
Allergic response
There are two subsets of T-cells Th1 and Th2. Both invoke different response to allergens. Th1 direct a non-allergic response while Th2 direct allergic response ranging from releasing of histamine to anaphylactic response. The presence of IL-12 cytokines direct a Th1 based, nonspecific response.
Mechanism of allergic response (interaction between helper T cell and B cell)
Step 1.
When allergen enter to body they are encountered by B cells. Immunoglobulin receptors on the surface of B cells recognize antigen (Peanut allergens) and get attached, which are then internalized and processed. Within B cells the fragments of antigens combine with HLA class 2 proteins.
Step 2
HLA class 2 with antigen fragments (peanut allergens) then display on the surface of B cells.
Step 3
Receptors on the surface of helper T cells recognizes the complex of HLA class 2 and antigen fragments (peanut allergen) and is activated to produce cytokines, which activate the B cells.
Step 4
B cell is activated by cytokines and begins clonal expansion. Some of the progeny become anti-body producing plasma cells while other become memory B cells.
The correct option is B. 80% of the radioactive phosphorus used in the experiment entered the cell showing that DNA was the hereditary material.
46 The normal human karyotypes contain 22 pairs of autosomal chromosomes and one pair of sex chromosomes (allosomes). Normal karyotypes for females contain two X chromosomes and are denoted 46,XX; males have both an X and a Y chromosome denoted 46,XY.
