Nitrification. The conversion of ammonium to nitrate is performed primarily by soil-living bacteria and other nitrifying bacteria. In the primary stage of nitrification, the oxidation of ammonium ( NH+4) is performed by bacteria such as the Nitrosomonas species, which converts ammonia to nitrites ( NO−2).
28. bacteria and fungi.
29. answer 3
30. answer 2
Helicase breaks hydrogen bonds of the DNA helix. Therefore it “unzips” the DNA helix and separates the strands for free complementary RNA strands which use the strands as a template during replication.
The answer is pronuclei. A pronuclei is the state of the
nucleus of either the sperm or the ovum after the sperm has entered the ovum
but the two nuclei have not yet fused. When the sperm enters the ovum, the membrane
of the sperm pronuclei dissolves hence leaving no barrier for the two genetic
materials to combine.