In a population,the number of pre-reproductive age organisms is more than the post-reproductive age organisms. As a result,the population will .....

Which one is correct for the logistic model of population growth?
$I.$ Population growth rate increases as the size of the population approaches the carrying capacity.
$II.$ All individuals have the same effect on population growth.
$III.$ There are unlimited natural resources.
$IV.$ As population increases,the competition goes on increasing.
Select the correct combination.

Give the differences between $S$-shaped and $J$-shaped growth curves.

If $N$ is the population density at time $t$,then its density at time $t+1$ can be calculated as . . . . . . .

Which of the following is correct for $r$-selected species?

Human population after the $17$th century $A.D.$ is thought to be in which phase?