How efficient both lungs and gills are in these crabs?

In crabs, gills are more inferior to lungs in O2 uptake, but they are both quite efficient.

Explanation:

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Both are used for oxygen intake and excretion

Explanation:

In all species, the lungs were extremely effective in oxygen uptake whilst the performance of the gills was inferior. An exception to this was Gecarcoidea natalis, which has gills highly modified for aerial gas exchange; its gills and lungs were equally efficient in O2 uptake. The relative efficiencies of the lungs and gills in CO2 excretion differed between species, with the gills being the major site of CO2 loss in the more amphibious species and the lungs having an increasingly important role in the more terrestrial crabs. The presence or absence of lung portal systems was not found to correlate with either saturation rates or efferent oxygen concentrations, with both lung types being extremely efficient in O2 uptake. The lungs with portal systems showed a large increase in oxygen content in the first lacunar bed and progressively smaller increases in the next two; these lungs may, therefore, have some reserve for exercise.

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.

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).