Give differences : Immigration and Emigration
Immigration | Emigration |
$(1)$ Inward movement into a local population. | $(1)$ Outward movement from local population. |
$(2)$ Increases population size and so gene pool. | $(2)$ Decreases population size and so gene pool. |
$(3)$ For better condition. | $(3)$ To defend from unfavourable conditions, like scarcity of food. Shelter or mate; natural calamaties like draught, floods etc. |
Exponential Growth curve is:
Which of the following contributes an increase in population density?
The birth and death rates of four countries are given below. Which one will have the least population growth rate?
$Country$ | $Birth\, rate$ $/1000$ | $Death$ $/1000$ |
$M$ | $15$ | $5$ |
$N$ | $25$ | $10$ |
$O$ | $35$ | $18$ |
$P$ | $48$ | $41$ |