Answer:
<h2>
Through production of news cell-surface proteins with a different molecular structure by each new generation. Letter B</h2>
Explanation:
The life cycle of theses paratises extracellular alternate between the salivary glands of the insect transmitter and the blood of the mammal. During the set prior to the entry into the host, the metacylic parasites express a dense over formed by the Variant Surface of Glycoprotein, after entering to the mammal host they transform into a morphology that stays in the bloodstream.
<em>The parasites have to manipulate hosts cells in order to avoid the production of antimicrobial molecules and to benefit from growth factor production.</em>
<em>Intracellular protozoa have a remarkable adaptive capacity as they are able to resist killing by remodelling the phagosomal compartments where they reside and by interfering with the signalling pathway that leads to cellular activation. </em>
both immigration and births add individuals to a population.
1. PbO is a possible formula units, since O has charge of 2- and Pb can have a charge of 2+ or 4+, if it uses the 2+ ion, the charges will balance out to form PbO. Li+ and B(3-) would have Li3B, Al(3+) and Pb(2+) are both positive charges and would not balance out, Cl- and O(2-) are both negative charges and would not balance out.
2. Iodine is a halogen, so it has a charge of -1. Calcium is an alkaline earth metal in Group 2, so it has a charge of 2+. Therefore, if they were to form a formula unit, the resultant would be CaI2 (2 iodine atoms of 1- charge are needed to balance out the 2+ charge on the calcium atom).
3. Strontium is an alkaline earth metal with a charge of 2+, while phosphorus has a charge of 3-. Therefore, to balance the charges out, we would need 3 atoms of strontium and 2 atoms of phosphorus. This would give the formula unit of Sr3P2.