A population splits into two or more groups and these groups occupy the different ecological zones. This is known as
Allopatric speciation
Sympatric speciation
Ecological speciation
None of the above
Which of the following is the correct sequence of events in the origin of life ?
$I.$ Formation of protobionts
$II.$ Synthesis of organic monomers
$III.$ Synthesis of organic polymers
$IV.$ Formation of $DNA$ based genetic systems
The basic unit of animal population which is communal interbreeding, in a species is known as