The disadvantages of the pyramid of productivity as a representation: The rate of biomass production of an organism is required, which involves measuring growth and reproduction through time. There is still the difficulty of assigning the organisms to a specific trophic level.
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D, think of it like a house.
Answer:
(d). B-cells.
Explanation:
Adaptive immunity can be described as immunity which develops in response to exposure to a pathogen (or foreign molecule). throughout the life. It is divided into two types, humoral immunity and cell-mediated immunity.
Humoral immunity is mediated by B cells that secrete antibodies against particular antigens. These antibodies recognize and neutralize the antigens and activate cell-mediated immunity, which is mediated by T cells.
Thus, the correct answer is option (d).
Answer:
In order to be useful in treating human infections, antibiotics must selectively target bacteria for eradication and not the cells of its human host. Indeed, modern antibiotics act either on processes that are unique to bacteria--such as the synthesis of cell walls or folic acid--or on bacterium-specific targets within processes that are common to both bacterium and human cells, including protein or DNA replication. Following are some examples.
Most bacteria produce a cell wall that is composed partly of a macromolecule called peptidoglycan, itself made up of amino sugars and short peptides. Human cells do not make or need peptidoglycan. Penicillin, one of the first antibiotics to be used widely, prevents the final cross-linking step, or transpeptidation, in assembly of this macromolecule. The result is a very fragile cell wall that bursts, killing the bacterium. No harm comes to the human host because penicillin does not inhibit any biochemical process that goes on within us.
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Explanation:
