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.
The symptoms of a lung-expansion injury tend to appear immediately after the dive while the symptoms of decompression sickness tend to appear usually slower after the dive.
Why does oxygen treat scuba-related illnesses?
Decompression sickness (DCS) patients address the disease process by dissolving air bubbles in the blood and tissues and diffusing excess nitrogen to oxygenate ischemic regions.
Needs to be recompressed Recompression was traditionally carried out with the assistance of a personal doctor or technician and a customized chamber that allowed for a controlled rise in atmospheric pressure. DCS divers have to travel further to decompression rooms since the number of rooms accessible for 24-hour emergency care countrywide is decreasing at an alarming rate.
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Answer:
Please find the explanation below
Explanation:
Sexual reproduction is the kind of reproduction that requires two organisms (male and female) to form an offspring. The male organism produces gametes called SPERM while the female organism produces gametes called EGG. These two gametes come together in a process called FERTILIZATION to produce a zygote, which develops into an offspring.
In sexual reproduction, gametes are produced by organisms involved via a process called MEIOSIS. Meiosis, however, reduces the chromosome number of the gametes by half. However, one process unique to only meiosis and sexual reproduction is called CROSSING OVER.
Crossing over is the process whereby chromosome segments is exchanged between non-sister chromatids of homologous chromosome. This process causes a recombination of chromosomes (alleles) in such a way that the gametes will be genetically different from the parent organisms (genetic variation). According to this question, sexual reproduction leads to more genetic variation than asexual reproduction due to the process of CROSSING OVER that occurs in sexual reproduction.
B 1/4 because i seen the question and answer on my test and got it correct
The correct answer is option eosinophil: bacterial macrophage
Eosinophil is responsible for defense against parasitic infections and few are involved in organ formation.
