In the life scale of mosquito, comma shaped stage is:
larval stage
pupal stage
imago stage
none of these
B.
pupal stage
The pupa of mosquito has comma-shaped body, consisting of a swollen, unsegmented cephalothorax and a slender depressed, 9-segmented abdomen under cephalothorax.
Removal of top fertile soil by wind or water is :
Siltation
Soil erosion
Weathering of soil
Leaching
Acid rain are produced by:
excess NO2 and SO2 from burning fossil fuels
excess production of NH3 by industry and coal gas
excess release of carbon monoxide by incomplete combustion
excess formation of CO2 by coinbustion and animal respiration
A student wants to study metaphasic behaviour of chromosomes in a living cell. The technique most suitable is :
phase contrast microscope
x-ray microscope
cell fractionation
scanning electron microscope
Two or more species occupying same or ovarlapping areas are :
sympatric
sibling
sub species
allopatric