The distribution of the human population on Earth is:

$A$ 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

Which type of population becomes more efficient in all work?

Members of the same species living in the same habitat interact with each other to form a ........ .

Read the following statements and choose the option with all the correct statements only :
$(A)$ The size of a population for any species is not a static parameter.
$(B)$ Total number is always the most appropriate measure of population density because in all cases it is most meaningful and easy to determine.
$(C)$ $A$ population growing in a habitat with unlimited resources shows initially a lag phase followed by phases of acceleration and deceleration and finally an asymptote.
$(D)$ According to ecologists,life history traits of organisms have evolved in relation to the constraints imposed by the abiotic and biotic components of the habitat in which they live.
Choose the correct answer from the options given below :

The tiger census in our national parks and tiger reserves is based on: