Question. 27 and 2 nd part that is "It is often that

Question. 27 and 2 nd part that is "It is often that now IS it SO. (a) Descrie 8.tt+Wetnberg' OR Sew bead to speciation? affected by the variations leading to speciation? 27. population has and not an individual organism. (S) Whet is population density? Explain any three different ways the population density can be measure 'AQh the help of an example each. "it S often said that the pyramid of energy is always upright. On the other hand, the pyramid of Sic—ess can Se both and inverted.- Explain with the help of examples and sketches.

Dear Student, 

Pyramid of energy is always upright because as per 10% law of energy transfer, only 10% of energy is transferred to the next trophic level. So, the producers always have maximum energy followed by primary consumers and least is with the highest trophic level.
The pyramid of energy appears as :

For the pyramid of biomass, it can be upright or inverted as it depends on the total mass of organisms on a particular trophic level. 
For example, for terrestrial ecosystem, the grasses are producers and have largest biomass followed by primary consumers and so on.
Inverted pyramid is there in case of phytoplanktons forms first trophic level and have smallest biomass.


Regards