Which of the following would necessarily decrease the density of a population in a given habitat?
Natality $>$ mortality
Immigration > emigration
Mortality and emigration
Natality and immigration
A protozoan reproduces by binary fission. What will be the number of protozoans in its population after six generations?
128
24
64
32
In 2005 , for each of the 14 million people present in a country, 0.028 were born and 0.008 died during the year. Using exponential equation, the number of people present in 2015 is predicted as
25 millions
17 millions
20 millions
18 millions
Amensalism is an association between two species where
one species is harmed and other is benefitted
one species is harmed and other is unaffected
one species is benefitted and other is unaffected
both the species are harmed.
Lichens are the associations of
bacteria and fungus
algae and bacterium
fungus and algae
fungus and virus