Question

Which are the four principles biological systems of Earth???​

Answer 1

${\underline{\boxed{\bf{\huge\purple {Answer :-}}}}}$

$\sf\mapsto\huge{Fisheries}$

$\sf\mapsto\huge{Grasslands}$

$\sf\mapsto\huge{Forests}$

$\sf\mapsto\huge{Crop \: lands.}$