1. Which of the following correctly compares the changes that take place in an ecosystem during primary succession and secondary
succession? (2 points) a) Primary succession takes place over a long period of time on newly formed land, while secondary succession occurs quickly in areas that have disrupted by a natural disaster.
b) Primary succession takes place quickly on newly formed land, while secondary succession occurs over a long period of time in an area that has been disrupted by a natural disaster.
c) Primary succession takes place over a long period of time in an area that has been disrupted by a natural disaster, while secondary succession occurs quickly on newly formed land.
d) Primary succession takes place quickly in an area that has been disrupted by a natural disaster, while secondary succession occurs over a long period of time on newly formed land.
2. Which of the following is an example of how a biotic factor can affect the population dynamics in an ecosystem? (2 points)
a)Lack of water during a drought causes many of the individuals in a population to die.
b) Seasonal temperature changes cause a species to migrate between two ecosystems.
c) Excessive rain and flooding cause organisms in an area to relocate.
d) The population of a predator increases following an increase in the population of its prey.
The correct answers are as follows: 1. A. There are basically two types of succession, they are primary and secondary succession. Primary succession refers to the type of succession that occurs in new and bare areas where the soil present is unable to sustain the growth of plants. An example of primary succession area is an area with sand dunes that is freshly formed. Primary succession usually occur over a long period of time. Secondary succession is a type of succession that occur on a land which was disturbed by hazardous events such as fire outbreak, flood, etc. Secondary succession occurs much faster than the primary succession.
2. D There are two types of factors that affect any particular ecosystem, these are abiotic and biotic factors. The abiotic factors refers to non living factors such as temperature, relative humidity, rainfall, etc. while the biotic factors refer to the living factors. Looking at the options given above, one will see that only option D has living factor, which is predators. All other options have abiotic factors.
