Botany Ecosystem questions from NEET UG 2008.
A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this (1) Lots of urea and phosphate fertilizer were used in the crops in the vicinity. (2) The area was sprayed with DDT by an aircraft. (3) The lake water turned green and stinky. (4) Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis. Which two of above were the main causes of fish mortality in the lake?
About $70 \%$ of total global carbon is found in
Consider the following statements concerning food chains A. removal of $80 \%$ tigers from an area resulted in greatly increased growth of vegetation B. removal of most of the carnivores resulted in an increased population of deers C. the length of food chains is generally limited to 3-4 trophic levels due to energy loss D. the length of food chains may vary from 2 to 8 trophic levels Which two of the above statements are correct?
Consider the following statements concerning food chains (a) Removal of $80 \%$ tigers from an area resulted in greatly increased growth of vegetation (b) Removal of most of the carnivores resulted in an increased population of deers (c) The length of food chains is generally limited to 3-4 trophic levels due to energy loss (d) The length of food chains may vary from 2 to 8 trophic levels. Which two of the above statements are correct?
Quercus species are the dominant component in
The slow rate of decomposition of fallen logs in nature is due to their