Checkpoint: Population Size

CheckPoint Population Size Day 5 week 4

*Resource: Ch. 7 Alien Invasion VLR

*View the Ch. 7 Alien Invasion VLR located under the Week Four Materials section of your student Web page.

*Post a 200- to 300-word response to the following:

o Explain the four factors that produce changes in population size.

There are four factors that produce changes in population each year. The first is birth rate. The birth rate is the number of births per each year. The second factor is the death rates. The death rates include the number of deaths per each year. Growth rate is also referred to as the natural increase of the human population. Then there is "Dispersal" which is the movement from one region or country to another. There are considered to be two types of dispersal which are immigration and emigration. Immigration is when person enter a population and increase the size of that population. Emigration is when a person leaves a population and decrease the size of it.

o Which factors affect population size in the video?

The major factors that affect population size in the video are the depletion of the land. With the nutria's living in the wetlands they destroy hundreds of acres of land throughout the wetlands each year. Since the female nutria is capable of birthing over forty babies a year, the population size seems to grow and grow. But when the wetlands become desolate to having the type of foods they eat, the population size could decrease with the amount of deaths each year due to the fact of the death rates increasing, because of the lack of food.

o What do you predict will happen to the nutria population after the land is depleted of the nutrias' food resource?

I predict that the nutria population will migrate to find food they can live on after the depletion of their food source. The nutria's already destroyed many acres of the wetlands, but in their defense, no-one can actually live in the wetlands since it is a layer of grass that is formed on top of water.