Human Body

Source: Pancreas of pigs and cows. Reason: Animal insulin caused allergic reactions in some patients due to structural differences from human insulin. (b) Why does the insulin synthesized in the human body undergo processing whereas the insulin produced by Eli Lilly company does not need to undergo any processing? Explain.
% Solution Solution: Human insulin is produced as proinsulin and requires processing to remove Cpeptide. Eli Lilly produces readytouse recombinant insulin without requiring further processing.

Polarity: 5 to 3 . Number of amino acids: 4 amino acids. Reason: Translation proceeds in the 5 to 3 direction, and the remaining codons in the segment can accommodate 4 amino acids.

Entry: HIV enters host cells (CD4+ Tcells) via surface receptors. Reverse transcription: Viral RNA is converted into DNA by reverse transcriptase. Integration: Viral DNA integrates into the host genome via integrase enzyme. Replication: Host machinery synthesizes viral components. Assembly and release: New viral particles are assembled and released, infecting other cells. Progression to AIDS: Gradual destruction of CD4+ cells leads to weakened immunity and opportunistic infections, culminating in AIDS.

Liver.

Entry: HIV attaches to CD4 receptors on T-cells and fuses with the cell membrane. Reverse Transcription: Viral RNA is converted to DNA by reverse transcriptase. Integration: Viral DNA integrates into the host genome via integrase. Replication: Host machinery synthesizes viral proteins and RNA. Release: New viruses assemble and exit, destroying T-cells over time. Progression: Immune system weakens, leading to opportunistic infections and AIDS.

If the ovum is not fertilised, the corpus luteum degenerates, leading to a decline in progesterone levels. Low progesterone levels cause the breakdown of the endometrial lining, resulting in menstruation.

The spleen is a large, bean-shaped organ located in the abdominal cavity. It acts as a blood filter by removing old and damaged red blood cells and pathogens. It also plays a role in the immune response.