Before it was banned in the united states in 1972, the pesticide ddt was used to treat wetlands where mosquitos breed. there, algae would accumulate ddt in their tissues. small aquatic animals such as mayfly nymphs would eat the algae. fish would eat the mayfly nymphs and osprey would eat the fish. which tropic level would have the highest ddt levels?

i'm pretty sure it's spores

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.