Homework Question on Biology and Life
- Compare exponential, logistic growth, population oscillation.
- Compare survivorship curves types I, II and III, with examples.
- Example of life history tradeoff.
- How does age structure of a population influence future growth? Describe the process known as the demographic transition. Under what circumstances does it occur?
- Describe how abiotic AND biotic factors influence species distributions.
- Describe energy flow within food webs. What is the 10% rule and what are the implications of this rule?
- Describe the basic cycling of carbon, nitrogen and phosphorus through ecosystems. What is a detritivore?
- What is an ecological niche? Describe the two possible outcomes when 2 similar species compete for the same niche (competitive exclusion, resource partitioning).
- Compare primary and secondary ecological succession.
Homework Answer on Biology and Life
1) Exponential growth occurs when the population rises by a certain factor after a successful period. It occurs when resources are abundant, exceed the carrying capacity of the ecosystem, and finally crash due to mass mortality. Logistic growth happens where population grows with limited resources until it reaches a steady phase and rarely crashes and does not exceed the carrying capacity of the ecosystem. Population oscillation refers to the increase and decrease of population especially in predator- prey competition.
2) Type I survivorship: Here the survivor rate is high during the early and middle life where rapid decline is experienced later in life, for instance in the case of humans and mammals. Type II survivorship indicates that there is constant death rate and probability of survivor is not dependent of age, for example in birds and lizards. Types III curves type indicate survival rate probability is high at late life compared hence high deaths at early stages of life, for example in marines invertebrates like oysters.
3) An example of life history tradeoff is genetic is maturity age.
4) Age structure influences future growth in that, if population has a high number of individuals at early and productive stage there are high chances of potential increase of population. Demographic transition is the change where by the number of born children increases compared to death rate resulting from nations developing to industrialized economy.