Secondary growth in monocotyledons

Due to lack of cambium in monocotyledons, secondary growth is absent. But Very few plants in monocots shows anomalous secondary growth such as Dracaena, Yucca, Aloe, Sansevieria and Agave

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#XL - T Zoology

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The inhaled bacilli are ingested by alveolar macrophages in the lung and inhibiting formation of phagolysosomes

CD4+ T cells are activated within 2 to 6 weeks after infection.

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These cells wall off the organism inside a granuloma called a tubercle. The localized concentrations of lysosomal enzymes in these granulomas can cause extensive tissue necrosis.

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Diphtheria

Natural infection with C. diphtheriae occurs only in humans and is spread by respiratory droplets. 

The organism colonizes the nasopharyngeal tract and causes little tissue damage, with only a mild inflammatory reaction. 

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Virulence is due to its potent exotoxin, which destroys the underlying tissue and results in heart, liver, and kidney damage, as well as to suffocation following formation of a tough fibrous membrane in the respiratory tract

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#XL - T Zoology

Malaria (Parasitic)

Sporozoites enter the bloodstream by mosquito.

The sporozoites migrate to the liver, where they multiply, transforming liver hepatocytes into giant multinucleate schizonts, which release thousands of merozoites into the bloodstream.