<span>The proteins that are embedded in the cell membrane act as channels to transport substances in and out of the cell.</span>
Answer:
The correct order would be:
A vaccine introduces a weakened flu virus into the body.
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The immune system identifies antigens on the weakened flu virus.
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Antibodies are produced, which bind to the weakened flu virus and signal immune cells to destroy it.
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The actual flu virus enters the body, and lymphocytes recognize the antigens.
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Antibodies are quickly produced and allow the body to fight off the infection.
Vaccination or immunization is the process which helps in developing the immunity (adaptive) against a particular pathogen or microorganism.
It includes the administration of antigen, weakened or heat-killed microorganism (such as flu virus) into the patients body. Body's immune system produces naive B and T cells to eliminate the antigen.
This encounter enables the immune system to produce memory B and T cells against that particular pathogen.
In future, whenever the same antigen enters the body, the immune system gets activated quickly due to the presence of memory cells. It enables the body to produce more effective secondary response against the pathogen.
Answer:Sclerenchyma
Explanation:Sclerenchyma is thick walled dead lignified cells, they are hard and elastic. The sclerenchyma cells are divided into two groups namely fibers and sclereids. Sclerenchymatous fibers are branched/unbranched, long, hard, pointed cells with tapering ends, thick walls, and narrow lumen.
The interaction between two polar molecules would involve HYDROGEN BONDS.
Polar molecules are molecules that have both positive and negative charges as a result of the differences in the electronegativity of the atoms that made up the molecule. Polar molecules interact through dipole dipole inter molecular forces and hydrogen bonds.
Answer:
The right answer is Letter A
Explanation:
The proposed model for the mechanism of initial transcription that suggests the entire RNA polymerase enzyme moves along the DNA is <em>transient-excursion model</em>, and the proposed model that is best supported by experimental findings is<em> scrunching model.</em>
<em>Because RNA polymerase leaves the promoter, translocate a short way along DNA template, synthesizes a short transcript before aborting transcript, releasing the transcript and returning to its original location on promoter. That is the transient-excursion model.</em>
<em>The scrunching model downstream DNA is pulled into the enzyme and has accumulated within the enzyme as single stranded bulges.</em>
<em>Experiments show that scrunching is right, experiments using single molecule analyses that allow the positions of different parts of polymerase to be measured relative to each other and to the template DNA during transcription.</em>
