Aerenchyma is the characteristics feature of
Mesophytes
Hydrophytes
Xerophytes
Aesophytes
Prolonged liberal irrigation of agricultural fields is likely to create the problem of
$5^{\text {th }}$ $June$ is celebrated as
Who defined ecology as the study of the relations of all organisms to all its environments
$A$ : Some organisms can maintain internal homeostasis by means of physiological processes and are called
'Regulators'.
$R$ : 'Regulators' can maintain internal homeostasis only upto a limit of stressful conditions.
The abundance of a species population within its habitat is called