Biology, 26.07.2019 06:40, poppy1173

The human immune system cannot effectively suppress the hiv virus on its own. what key feature of hiv makes it so hard to beat? the human immune system cannot effectively suppress the hiv virus on its own. what key feature of hiv makes it so hard to beat?

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The immune system recognizes HIV by its antigen shape. But, just when the immune system recognizes one shape, HIV may multiply and change the shape of its antigen. HIV can "hide" from the immune system for a long time. When HIV infects a cell the virus may make more viruses and infect more cells or lie quietly in a cell for a long time. If HIV doesn't reproduce, the immune system can't find it and destroy it. HIV destroys the immune system. The Immune system consists of Innate Immunity and Humoral Immunity Innate Immunity is Non-specific Immunity, whereas Humoral Immunity is specific Immunity. T-cells produce Cell-Mediated Immunity and B-cells produces Humoral Mediated Immunity. As HIV destroys more and more helper T cells, the immune system begins to break down. Finally the immune system can no longer kill HIV or any other invading germs and a person infected with HIV is diagnosed with AIDS.

answered: Guest

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

answered: Guest

transcription is a process in which information is rewritten. it is something our cells must do, in a more specialized and narrowly defined way. in biology, transcription is the process of copying out the dna sequence of a gene in the similar alphabet of rna. it needs to happen in the nucleus because that's where the dna is. dna is always inside the nucleus unless the cell is dividing.

transcription is the first step in gene expression, which involves copying a gene's dna sequence to make an rna molecule. transcription is performed by rna polymerases. it has three stages: initiation, elongation, and termination. rna molecules must be processed after transcription in eukaryotes.

explanation:

long version:

the protein synthesis consists two processes which are, transcription and translation. transcription takes place in the nucleus. it uses dna as a template to make an rna molecule. rna then leaves the nucleus and goes to a ribosome in the cytoplasm, where translation occurs. transcription is the first part of the central dogma of molecular biology: dna → rna. it is the transfer of genetic instructions in dna to messenger rna (mrna). during transcription, a strand of mrna is made that is complementary to a strand of dna.

these three stages are:

initiation: in which is the beginning of transcription.occuring when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

elongation: in which is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

termination: in which is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.

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The human immune system cannot effectively suppress the hiv virus on its own. what key feature of hi...