(N/A) $\rightarrow$ The Earth hosts an immense variety of living organisms.
$\rightarrow$ According to surveys,the number of species known and described ranges between $1.7-1.8$ million.
$\rightarrow$ This number refers to the biodiversity on Earth.
$\rightarrow$ The term biodiversity or biological diversity refers to the number and types of organisms present on Earth,representing the forms of life in the living world.
$\rightarrow$ The living world includes all living organisms such as microorganisms,plants,animals,and humans.
$\rightarrow$ Biodiversity is not limited to currently known life forms.
$\rightarrow$ As we explore new areas,or even re-examine old ones,new organisms are continuously being discovered and added to the list.
$\rightarrow$ This vast variety cannot be studied or identified without a proper system of classification and nomenclature.