Answer:
<em>The correct option is d) once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity.</em>
Explanation:
In the field of biology, the all-or-nothing law can be described as a principle which focuses on the strength with which a nerve or muscle fibre responds to a particular stimulus, this strength being independent of the strength of the stimulus. The functioning of the impulse is just like the trigger of a gun. The more the force of a stimulus, the more will be the intensity of the nerve impulse.
Fakse Breeding stock should not be given implants
Answer:
A missense mutation is a mistake in the DNA which results in the wrong amino acid being incorporated into a protein because of change, that single DNA sequence change, results in a different amino acid codon which the ribosome recognizes. Changes in amino acid can be very important in the function of a protein.
The answer is the vitamin B 6 supplement can cause irreversible nerve damage. Taking too many vitamins can cause also a toxic effect on our body. Too much vitamin B6 can also cause oversensitivity to sunlight, which can lead to skin rashes and numbness, as well as nausea, vomiting, abdominal pain, loss of appetite, and abnormal liver function.
In immunology two types of immune response are described depending on whether there is prior contact with the antigen.
• At this first contact, only lymphocytes with receptors specific to the antigen in question are stimulated and lead to the production of antibodies capable of neutralizing it. The lymphocytes capable of recognizing a specific antigen are very few and the production of antibodies - of low intensity and limited duration - is detectable only after a period of latency of several days. This is called the primary response. The specificity of the resulting seropositivity, however, makes it possible to detect contamination (seroconversion).
• Upon re-contact with an antigen that has already triggered a primary response, specific antibody production is found to increase rapidly after a short latency period. The secretion of IgG then reaches levels much higher than those observed during the primary response, while that of IgM is of the same order. This early and intense response, called secondary response, most often results in the destruction of infectious agents before any clinical sign.
• Many centuries before the discovery of microbes, it was noted that people who developed a contagious disease without death were then specifically immunized against the disease, without being protected against others.
• The ability to react appropriately to an already received stimulus supposes the existence of a memory. The immune memory is based on the existence of memory B and T lymphocytes, resulting from the clonal expansion due to the first contact with the antigen. Their lifespan is significantly higher than that of other lymphocytes and their high reactivity gives its rapid and intense character to the secondary response.
