Answer:
The correct answer will be option - D.
Explanation:
Slime moulds are the fungus-like protists which bear a structure called sporangium which produces spores. The sporangium is produced in fungi as well due to which these protists are called fungus-like. Although both produce sporangium but they are not closely related, rather they are distantly related organisms.
The appearance of a sporangium in both indicates that they had faced the same conditions due to which they both showed the same adaptation by producing the same structures performing the same function. In evolutionary terms, this is an example of convergent evolution.
Thus, option D is the correct answer.
An organism that makes its own food is a producer.
<u>Answer:</u>
<em>A constant is something whose value cannot be changed and is used for comparison purpose. </em>
<u>Explanation:</u>
The controlled variable is a type of variable whose value is kept constant during the experiment to get the desired or expected result. The difference between constant and a control variable is that the constant can never be changed.
However, the value of control variable can be changed but is kept constant with a purpose in an experiment to get the data. The controlled variable in a battery can be the multi meter that should be used for all the batteries.
The cell wall gives strength to a cell.
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.
