Insects are the most diverse group of organisms, in terms of numbers of species, dominating terrestrial habitats. more than 30 orders of insects have been described, with the order coleoptera being the largest. classification is based on traits such as wings and mouthparts. all insects have a three-part body plan consisting of a head, thorax, and abdomen; three pairs of walking legs; and one or two pairs of wings. the chart below indicates defining characteristics for eight of the more than 30 orders of insects.

a

explanation:

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.