Hello there,
Your answer would be "Dissolved Oxygen"
Hope this helps
~HotTwizzlers
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.
Out of the choices given, active and passive transport of solutes across a membrane typically differ because active transport always involves the utilization of cellular energy, whereas passive transport does not require cellular energy. The correct answer is B.
Answer:
the correct answers are as follows
12:
b. Testcross- an organism with dominant phenotype but unknown genotype is crossed with homozygous recessive organism for the same trait. Based on the results obtained, if all offsprings have the same phenotype, then the parent is homozygous, but when a 1:1 ratio is observed in the offsprings, then the parent is heterozygous.
13.
e. Watson and Crick- they both used the crystallographic images from Franklin, analyzed them to first elucidate the 3D structure of the DNA and propose it to the world.
14.
c. Intracellular and commonly found in the cytoplasm- the receptors of steroid hormones are generally present within the target cell either in the cytoplasm or nucleus, since they alter gene expression.
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e. Certain prokaryotes/bacteria- this is a process that will enable disease-causing pathogens to communicate and cooperate with their group, by the release of autoinducers that increase their cell density.
Trace fossil because a trace fossil is a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
