Answer:Amphibians evolved during the middle of the Devonian period (416 to 359 million years ago) from the lobe-finned fish of the vertebrate class Sarcopterygii. Species within the genus Ichthyostega (members of the Labyrinthodontia subclass) are considered by some scientists to be the earliest amphibians.
Explanation:
The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. Memory B cells of the immune system will protect her from getting the same cold again.
In immunology, a memory B cell (MBC) is a type of B lymphocyte that forms part of the adaptive immune system. These cells develop within germinal centres of the secondary lymphoid organs.
Memory B cells circulate in the blood stream in a quiescent state, sometimes for decades. Their function is to memorize the characteristics of the antigen that activated their parent B cell during initial infection such that if the memory B cell later encounters the same antigen, it triggers an accelerated and robust secondary immune response.
Memory B cells have B cell receptors (BCRs) on their cell membrane, identical to the one on their parent cell, that allow them to recognize antigen and mount a specific antibody response.
Learn more about memory B cell here : brainly.com/question/23423029
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Answer:
a
Explanation:
this image shows what each letter changes to.
Hi,
The answer is A.
"The sensation stage of the erotic stimulus pathway theory is similar to the excitement and orgasm phases of the epor model."
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r3t40
