Organisms and Populations Question 52

52. What is true about the isolated small tribal populations?

[2008]

(a) There is a decline in population as boys marry girls only from their own tribe.

(b) Hereditary diseases like colour blindness do not spread in the isolated population.

(c) Wrestlers who develop strong body muscles in their life time pass this character on to their progeny.

(d) There is no change in population size as they have a large gene pool.

Show Answer

Answer : a

Hints & Solutions

(a) There is a decline in population as boys marry girls only from their own tribe in the isolated small tribal populations. This is because at some stage marriage will stop due to isolation (neither immigration nor emigration will occur) and on the other hand, marriages within same tribe will lead to homozygosity of disease and ultimately death. Thus, leading to decline in population.