Water hyacinth
Find the odd one out
(1) Eichhornia crassipes
(2) Introduced in India for their lovely flowers
(3) Have mauve colored flowers
(4) Does not has any characteristic shape
Water hyacinth is not
(1) World's most problematic weed
(2) Terror of Bengal
(3) Grow abundantly in eutrophic water bodies
(4) Maintains a balance in the ecosystem dynamics of the water body
Sewage has heavy metals
(1) Elements with density greater than 5g /cm3
(2) Elements with density greater than 10g /cm3
(3) Elements with density greater than 15g /cm3
(4) Substances with density greater than 0.3g/cm3
Increase in the concentration of the toxicant at successive trophic levels is called
(1) Biopiracy
(2) Biomagnification
(3) Biomanagement
(4) Biosystematics
Biomagnification is a well known phenomenon for
(1) Mercury
(2) DDT
(3) Silver
(4) Both A and B
Concentration of DDT in water is 0.003 ppb, what can be the most commonly seen concentration of DDT in zooplankton?
(1) 4 ppb
(2) 5 ppm
(3) 0.04 ppm
(4) 2 ppm
Biomagnification of DDT in a fish eating bird can reach to
(1) 20 ppm
(2) 20 ppb
(3) 25 ppb
(4) 25 ppm
Why does biological magnification happen?
(1) The toxic substances can be digested but are not metabolised by our body
(2) The toxic substances can neither by digested nor be metabolised and just pass on to the next generation
(3) The toxic substances causes genetic mutation that pass to next generation
(4) Both B and C
High concentration of DDT directly disturbs
(1) Calcium Metabolism in birds
(2) Thinning of eggshell
(3) Premature breaking of eggshell
(4) Decline in bird population
when lake is young, the water is
(1) Cold and clear
(2) Warm and turbid
(3) Cold and turbid
(4) Warm and clear