If a population adds $20$ new individuals per year and the total population after $2$ years is $75$,what was the initial population size?

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.

The apex of the age pyramid of a stationary population is

For bacterial growth in a cell culture,the growth law is very similar to the law of radioactive decay. Which of the following graphs is most suitable to represent bacterial colony growth?

An asymptote in a logistic growth curve is obtained when:

The carrying capacity of the Earth for the human population is estimated to be approximately: