The answer to your problem is question 3 i just took that test i got it right
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:
1.Continuous diffusion of negatively charged ions into the postsynaptic neurons , <u>which leads to continuous reversal of charges (hyperpolarization) and therefore continuous firing of action potential</u>
2. Inhibition of hydrolytic enzymes e.g (acetycholinesterase) that metabolize activities of cholinergic neurotransmitters e,g acetycholine at post synaptic cleft. leading to firing of action potential.
Explanation:
Neuron whose dendrites transmits action potential to the neuromuscular junction is called presynaptic neuron. While neuron that transmit action potential away from the neuronal synaptic junction, or from the neuromuscular junction to the cell body of adjacent neuron or to effectors (gland and muscles) are called post synaptic neuron.
The more negatively charged ions that diffused into the post synsptic neuron, the more depolarization, and the greater the frequency of action potential produced
The inhibition of activities of hydrolytic enzyme which metabolize cholinergic neurotransmitter leads to continuous excitatory activities of cholinergic neurotransmitters on the receptors at the postsynaptic neuron, and the more action potential
