MCQ
Primary productivity:
- AIs equal to the standing crop of an ecosystem.
- BIs greatest in freshwater ecosystems.
- CIs the rate of conversion of light to chemical energy in an ecosystem.
- DIs inverted in some aquatic ecosystems
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$R$ : Biomass of fishes far exceeds that of phytoplanktons.
$I$. Each cell of sporogenous tissue in anther is capable of giving rise to microspore tetrad.
$II$. The pollen grain represent male gametophyte.
$III$. Pollen grains are usually triangular and $10-15 \mu m$ in diameter.
$IV$. Sporopollenin is one of the most resistance organic material which can be destroyed only by strong acids
and alkali.