Trypanosome infections evade attacks by host immune systems through which of the following mechanisms? A. insertion of its DNA i
nto the nuclear DNA of host cells B. production of toxins that kill lymphocytes C. infection of lymphocytes leading to a decline in the host's ability to fight infection D. production of new cell-surface proteins with a different molecular structure by each new generation
The correct answer is D. production of new cell-surface proteins with a different molecular structure by each new generation
Explanation:
Trypanosomes infections is famous for evading the immune response of the body because it has the ability to make change in its variant surface glycoprotein having different molecular weight and this phenomenon is called antigenic variation.
So adaptive immune system is not able to recognize the trypanosome by its glycoprotein because the old surface glycoprotein against which the memory cells were produced previous time is now changed.
Therefore the immune system will not recognize the new generation of trypanosome with different variants of cell surface glycoprotein. Therefore the right answer is D.
Placer mining can be less damaging to the environment than surface mines, as the sediment is returned to the water after the minerals have been extracted.
