(a) Explain primary productivity and the factors that influence it.

(b) Describe how to oxygen and chemical composition of detritus control decomposition.

OR

(a) What is El Nino effect? Explain how it accounts for biodiversity loss.

(b) Explain any three measures that you as an individual would take, to reduce environmental pollution.

a) Primary productivity is the total amount organic matter produced by plants by the process of photosynthesis. It is of two types:-

1) Gross Primary Productivity (GPP)

2) Net Primary Productivity (NPP).

NPP = GPP - Respiratory loss

b) Oxygen is an important factor for decomposition of detritus as decomposers are aerobic in nature thus require oxygen for normal functioning. Therefore anaerobic conditions decrease the rate of decomposition.

Chemical Composition also plays an important role as it decides the time taken by decomposers to degrade the components of detritus as for e.g. if lignin or chitin or cellulose is present then it takes long time to decompose and on the other hand if sugar or other soluble components are present then they take less time to decompose.

OR

a) El Nino effect is the abnormal change in the weather pattern near the equator in the Pacific ocean. Due to the heat of the sun the winds in the region are hot and thus causing evaporation of large quantity of water thereby leading to the formation of rain clouds and thus more rain. These abnormal warm west trade winds, hot climate and rains constitute the El Nino effect.

Various effects which lead to cause of biodiversity loss are :-

i) Increased Forest fires and drought.

ii) Increased water precipitation and floods.

iii) Increased sea surface temperature.

iv) Nutrient shifts.

v) Ocean Current Shifts.

vi) Coral Bleaching.

All these adverse effects ultimately cause the loss in biodiversity (both flora and fauna included) of a particular region .

b) The three measures I would take to decrease pollution are :-

i) Reduce the use of fossil fuels and shift to newer energy sources.

ii) Better norms, rules and quality checks and technology for pollution control in vehicles.

iii) Better waste disposal techniques.