<span>Pathogenic bacteria are the disease causing bacterias
Infection occurs when </span>viruses<span>, </span>bacteria<span>, or other </span>microbes <span>enter your body and begin to multiply. Disease, which typically happens in a small proportion of infected people, occurs when the cells in your body are damaged as a </span>result<span> of infection, and </span>signs and symptoms<span> of an illness appear.</span>
6. a, 7. c, 8. b , 9. e , 10. d , 11. e, 12.c
a) precipitation is balanced by evaporation
<span>During nitrification, ammonia is changed back into nitrate.</span>
Nitrification is a three-step process of oxidation of ammonia. It is an aerobic process performed by small groups of autotrophic bacteria (<span>Nitrosomonas,
Nitrobacter</span>).
First step- ammonia to hydroxylamine,
Second step-hydroxylamine to nitrite,
Third step-nitrite to nitrate.
Nitrification together with ammonification is part of a nitrogen cycle.
<span>A solution is the mixture of two or more substances. One of them is called the solute and the other is the solvent. A solute is the substance to be dissolved (sugar). The solvent is the one doing the dissolving (water). Therefore, suder is the solute and water is the solvent. Option C is the correct answer.</span>