How can students in the photograph use the net to sample the invertebrates in the river.

Answer and Explanation:

Macroinvertebrate communities show spatial and temporal variability. Many taxons have more affinity for one specific type of habitat.

There are two principal sampling techniques. Qualitative and cuantitave. Qualitative techniques provide data about the river richness and the relationship between the different taxonomic group's abundance. They allow the obtention of the most representative and abundant taxons, estimates their densities, biomass, and calculates the diversity indexes for each sampling site by period. Nets are needed to sample.

Every possible microhabitat must be sampled. The use of the different sampling elements depends on the substrate.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.