density: dependent & independent

Question 1

Define Density

Answer 1

number of individuals of a population, located in the same area within a specific time period

Question 2

Differentiate between density dependent and density independent factors

Answer 2

Dep: prevent overpopulation to maintain a stable population

Indep: factors are not related to the population density and are independent of * the numbers of a population

Question 3

List the 5 dependent factors and explain what they are

Answer 3

Food and water: The greater the number of individuals, the more food and water is needed.

Competition: The greater the number of individuals, the more they compete for resources ensuring survival of the fittest.

Space and shelter: The greater the number of individuals, the less space and shelter is available which results in high levels of stress. Stress: decrease in the fertility and natality rate of the population.

Predation: The survival of the predator depends on the number of prey available. The larger the prey population, the easier it is for the predator to catch the prey. Less prey results in the predator having to work harder to catch its food and may result in the predator starving.

Disease: Disease spreads quickly when overcrowding occurs.

Question 4

List the 2 density independent factors

Answer 4

Natural catastrophes: This includes droughts, hurricanes, earthquakes and floods. The population density is reduced non-biologically.

Climate: Severe temperatures affect population numbers. During a very cold winter, individuals die, even though food may be available. The strongest survive = natural selection; food shortage. In this case, the weaker individuals * * within population die of starvation