The morphology and natural history of a common and widely distributed butterfly was observed over a 25-year period in Costa Rica. Recent DNA barcoding (DNA sequence analysis) showed that what was once thought to be a single species is actually a complex of at least 10 species. Though caterpillars of these species eat different food plants and have somewhat different habitat preferences than their adult forms, their morphological differences are subtle. These butterflies would be considered species.

c.           is the correct answer

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.