Biology Past Questions and Answers

I. High birth rate and high immigration rate II. Low birth rate and high immigration rate III. Low mortality rate and low emigration rate IV. High mortality rate and high emigration rate. Which combination of the above can cause rapid over-crowding in climax biotic communities and human settlements? 

The number of plant species obtained from a population study of a garden is as follows: [i]Guinea grass[/i] (15), [i]Ipomoea spp[/i] (5), [i]Sida spp[/i] (7) and [i]Imperata spp[/i] (23) What is the percentage of occurrence of [i]Imperata spp?[/i]

When a marine fish was taken from the ocean and put in a tank of fresh water, it died after a short period because? 

If a DNA strand has a base sequence TCA, its complementary strand must be?

The appendicular skeleton is composed of the pectoral girdle?