Biology GK Questions Quiz-61

1201.Xenobiotics which are inherently resistant to microbial attack are called as: (1) Biodegradable (2) Persistent (3) All of the given options (4) Recalcitrant Answer: 1201.(4) The compounds that resist biodegradation and thereby persist in the environment are called recalcitrant. The recalcitrant xenobiotic compounds can be grouped into the following six types: (i) halocarbons; (ii) polychlorinated biphenyls; (iii) synthetic polymers; (iv) alkylbenzyl sulphonates; (v) oil mixture and (vi) others. 1202.In the grass lands, trees do not replace the grasses as a part of an ecological succession because of (1) Limited sun light and paucity of nutrients (2) None of the options (3) Insect and fungi (4) Water limits and fire Answer: 1202.(4) Grass ecosystems are an early stage of succession in regions where the mature ecosystems are forests. However, grass ecosystems are climax ecosystems in grassland regions, where there is not enough rainfall to support a forest. Due to limiting factors such as water s…