$I.$ Population evolve to maximise their reproductive fitness, also called Darwinian reproductive fitness (higher $r$ value), in the habitat in which they live
$II.$ The population growth rate $r$ is inversely related to generation time
$III.$ The housefly, which has a short life span and produces a large number of eggs, could be considered as a ' $K$ ' selected species
$IV.$ Under a particular set of selection pressures, organisms evolve towards the most efficient reproductive strategies
$V.$ Life history traits of organisms have evolved in relation to the constraints imposed by biotic and abiotic factors in their habitat Select the combination of correct statements
$I, II$ and $III$
$I, III$ and $IV$
$I, III$ and $IV$
All except $III$
When there is an exponential growth in a population, then it will be called as
Exponential growth in plants can be expressed as
A biologist studied the population of rats in a barn. He found that the average natality was $250$, average mortality $240$, immigration $20$ and emigration $30$. The net increase in population is