Which model is considered a more realistic one?

In the logistic growth equation $dN/dt = rN[(K-N)/K]$,'$r$' represents :-

$A$ given habitat has enough resources to support a maximum possible number of a species. This limit beyond which no further growth is possible is called its . . . . . . for that species.

$A$ population of $Paramecium$ $caudatum$ was grown in a culture medium. After $5$ days,the culture medium became overcrowded with $Paramecium$ and had depleted nutrients. What will happen to the population,and what type of growth curve will the population attain? Describe the growth curve.

Which type of population growth curve is expected for the human population in the coming century?

If the population size at time $N_{t+1}$ is $1000$,and there is no immigration or emigration,and the death rate is $50\%$ less than the birth rate,and the population size $1$ year ago $(N_t)$ was $800$,what is the number of births?