William Pak

Ecology Exam Corrections

Question 1: C – Ecosystems contain communities, communities contain populations, and populations contain individuals. This is the correct order for most to least inclusive.

Question 5: C – One is observing immigrant mice. The female mice couldn’t be dying before reproducing or else there wouldn’t be a high population density. This habitat couldn’t be a good place for them to reproduce since there aren’t any reproductive female mice. There is no such thing as a selective predation on female mice, and if there was there couldn’t be a high population density. It is unknown exactly when mice choose to breed but in this case it is unlikely that the breeding season is over.

Question 6: D – The red squirrels. Territorial squirrels will probably take more time and defend a certain area – which renders them to exhibit uniform dispersion. Lake trout will seek certain waters, dwarf mistletoes grow only in certain areas, cattails’ growth areas are restricted, and moths wouldn’t exhibit uniform dispersion.

Question 7: E – Marked and unmarked individuals have the same likelihood of being trapped – their being marked doesn’t make them more likely to be caught than the unmarked ones. One must also assume that the marked individuals have thoroughly mixed with the population – naturally they would want to return to their habitat. Also, it has to be assumed that no individuals have entered or left the population through immigration or emigration and that no individuals have been added by birth or death during the estimate. The exception is when there are equal proportions of deaths for marked and unmarked individuals during the sampling period.

Question 13: E – Pacific salmon and annual plants are organisms that reproduce once before they die.

Question 20: E – Cryptic coloration is when an organism appears to blend in with its surroundings to hide itself from its predators. A “walking stick” or stick bug is a perfect example of cryptic coloration.

Question 23: D – Their fundamental niche has been expanded. This means that they have negated the effects of the housing and agricultural development. A fundamental niche is where a species can live whereas a realized niche is where the species does live, since the factors like housing and agricultural development have forced the species to move away from parts of the fundamental niche.

Question 29: C – It could be a primary consumer because it would be herbivore and would devour plants.

Question 33: C – Materials are repeatedly used and are therefore recycled. Energy flows in and out of ecosystems and while one might say it is reused it is more