Chapter 45 & 47

Connection:

a. carrying capacity and biotic potential: The biotic potential is the maximum rate that a population can grow under ideal conditions. The carrying capacity is the maximum number of individuals an environment can contain. These work together because the biotic potential may have to yield to the carrying capacity and therefore the environment must be able to sustain the whole population or many will die.

b. biological magnification and trophic level: The trophic level is all organisms having the same number of transfer steps away from the energy input into an ecosystem while the biological magnification is the increasing concentration of a slowly degradable or non degradable substance in body tissues as it is passing along in the food chains. Both processes deal with energy being inputted into a larger system. In addition each species is put on a trophic level as a smaller organism is eaten by a bigger one and the process continues, this can lead to a biological magnification.

c. Detrivores and autotrophs: Detrivores are animals that feed on decomposing matter or organisms and an autotroph is an organism that synthesizes its own food from simple inorganic compounds in its environment with energy from the sun. These two are similar for instead of feeding off of living organisms, they find their food through what the ecosystem provides for them, autotrophs being the sun and detrivores feeding off organism that are already decomposed.

A)

45.4: limits on the Growth of Populations

1) Density-Dependent Limiting Factors

a) Many times the environmental factors keep a certain population of species from growing to its biotic potential

b) When resources of a specie or organism is lower in numbers, this supply is called the limiting factor

          - This can be extrensively detrimental to a population and one factor can affect the whole population

2) Carrying Capacity and Logistic Growth

     a) In the end, it is the sustainable supply of resources that will determine population   size

     b) the carrying capacity is the maximum number of individuals of a population given   the sustainable supply

     c) The pattern of logistic growth is used to show how the carrying capacity can affect           a population size

     d) When exponential or logistic growth are overcrowded, factors function as density-  dependent controls putting an individual’s survival over the population.

3) Density-Independent Limiting Factors

     a) Density-independent factos cause more deaths and fewer birth rates

B)

Survivorship curve: a graph line that emerges when ecologists plot a cohort’s age-specific survival habit.

Type I: Type I These curves are used to indicate population and it curves when there is a drop of survival during their lifetime.

Ex. The population of people in America who have easy access to health insurance as opposed to some of the starving children in Africa then the curve would drop because of the population, if the whole world is taken into consideration, will drop.

Type II: This curve reflects the death rate of all ages this includes all organisms.

Ex. The death of snowy egrets is very constant.

Type III: This curve is used to describe organisms with high death rate at an early stage in life.

Ex. Sea star larvae die at a very early age.

C)

a. Negative Growth: A negative growth population has a small amount of individuals in its pre-productive time with a higher amount when it is productive and after the productive stage is when the largest number of individuals can exist.

b. No Growth: A population with no growth steadily declines but as it gets older, it would have a smaller population.

c. Rapid Growth: A population with rapid growth has a dramatic increase in its population as the years go on.

d. Slow Growth: A population with slow growth is when the growth of a population decreases at a consistent rate.

D) The nitrogen cycle is when gaseous nitrogen is changed into ammonia (N2 à NH3). This occurs when the ammonia created by nitrogen-fixing bacteria in the soil and nitrogen fixation happen. Then the organisms use the two forms, nitrate and ammonium to live. Then as organisms pass on, they decompose and nitrogen enters back into the soil. And in the soil, the nitrogen is absorbed and nitrate is converted to gaseous nitrogen again.