(a) State how the constant internal environment is beneficial to organisms.
(b) Explain any two alternatives by which organisms can overcome stressful rxternal conditions.

Explanation

(a) Homestasis is the property of sysytem in which variables are regulated so that internal conditions remain stsble and relatively constant . Examples of homeostasis include the regulation of temperature and the balance between acidity and alkalinity (pH). .It is a process that maintains the stability of the human body's interna environment in response to changes in external conditions.
(b) The organims can overcome stressful external conditons in the following manner :
(i) Migrate : Herein the organims move from a stressful habitat to a more hospitable area and return when favourable conditions appoach . For eg : The Keolado National Park in Rajasthan hosts thousands of migratory birds from Siberia.