(a) Explain giving reasons why the tourists visiting Rohtang Pass or Mansarovar are advised to resume normal active life only after a few days of reaching there.
(b) It is impossible to find small animals in the polar regions. Give reasons.
(a) Tourists visiting high altitude areas such as Rohtang Pass or Mansarovar, experience altitude sickness. Its symptoms include nausea, fatigue and heart palpitations. This is because in the low atmospheric pressure of high altitudes, the body does not get enough oxygen. But, gradually we get acclimatised and stop experiencing altitude sickness. The body compensates low oxygen availability by increasing red blood cell production, decreasing the binding affinity of hemoglobin and by increasing breathing rate. Thus, the visitors are advised to resume their normal active life involving heavy works only after few days because for doing heavy tasks our body needs energy and this energy is obtained by the oxidation of glucose in the presence of oxygen which is a limiting factor in higher altitudes.
(b) Smaller animals are rarely found in Polar Regions because small animals have a larger surface area relative to their volume. Since heat loss or heat gain is a function of
surface area, they tend to lose body heat at a very fast rate when it is cold outside; because of which they have to expend much energy to generate body heat through metabolism.If the population growing exponentially doubles in size in 3 years, what is the intrinsic rate of increase (r) of the population?
List any three important characteristics of a population and explain.
With the help of suitable diagram describe the logistic population growth curve.
(a) adaptations of desert plants and animals.
(b) adaptations of plants to water scarcity.
(c) behavioural adaptations in animals.
(d) importance of light to plants.
(e) Effect of temperature or water scarcity and the adaptations of animals.
Define the following terms and give one example for each:
(a) Commensalism
(b) Parasitism
(c) Camouflage
(d) Mutualism
(e) Interspecific competition
Select the statement which explains best parasitism.
(a) Hiberation and aestivation
(b) Ectotherms and endotherms.
Give an example for:
(a) An endothermic animal
(b) An ectothermic animal
(c) An organism of benthic zone
'Analysis of age-pyramids for human population can provide important inputs for long-term planning strategies.' Explain.
(a) List the different attributes that a population has and not an individual organism.
(b) What is population density ? Explain any three different ways the population density can be measured, with the help of an example each.