population growth

• what is meant by the term population


  a group of interbreeding organisms of the same species occupying a particular habitat
• what are the four factors that will cause the population numbers to fluctuate in an ecosystem


  birth rate , death rate, immigration and emigration
• what word is best used to describe an ecosystem and why


  dynamic because they are always subject to change
• what is meant by birth rate


  the rate at which individuals reproduce
• what is meant by death rate


  the rate at which individuals die
• what is another term for death rate


  mortality rate
• what is meant by immigration


  the movement of individuals into a population of the same species
• what is meant by emigration


  this is the movement of individuals out of a population of the same species
• what would happen to the population size of birth rate and immigration is larger than death rate and emigration


  it would increase
• when is growing population growth of bacteria and yeast would it be correct to use the term birth rate if not what could be used instead


  no cell division
• how is the equilibrium of species controlled within a stable habitat


  through competition
• what is meant by sigmoidal shape


  s-shaped
• what does a population growth curve for an equilibrium species look like


  a curve upwards
• what is the first phase on a population growth curve


  the lag phase
• what is the second phase after the lag phase on a population growth curve


  the log growth phase
• what is the third phase of the population growth curve after the log growth phase


  stationary phase
• what is the fourth and final phase of the population growth curve after stationary phase


  death phase
• what is the lag phase of a population growth curve


  this is a period of slow growth and intense metabolic activity such as enzymes synthesis
• to what point in species growth does the lag phase of the population growth curve end


  sexual maturity
• at what point will the lag phase end in yeast


  in the time it takes to hydrate
• what is the exponential log phase of the population growth curve


  this is a phase in which there is a rapid increase in population numbers as more individuals are available to reproduce
• can the log phase last indefinitely if no explain why


  no because environmental resistance occurs at the end of the log phase
• what is meant by environmental resistance


  these are the factors that may limit the growth of a population
• what environmental resistance will occur for bacteria in a flask


  glucose availability ,overcrowding and toxic waste build-up
• what environmental resisting will cure for rabbits on a new Island


  predation ,parasitism and disease and competition for food
• what is meant by the stationary phase in the population growth curve


  is a stage in which birth rate is equal to death rate
• when will the stationary phase of the population growth curve end


  what the population has reached its carrying capacity
• what is meant by carrying capacity


  the number of organisms a given region or habitat can support without degrading the environment
• what is meant by death phase of the population growth curve


  this is the point in which environmental factors now result in a increased death rate that is larger than the birth rate
• give an example of environmental factors that can cause the death rate to increase , in yeast


  running out of glucose a nutrient broth