Question

Define ecology. Discuss what criteria influence population growth and how different species interact with one another, providing at least 3 types of examples . List the three criteria necessary for ecosystem survival. Define and/or describe each criterion.

Answer 1

1. Ecology is the branch of science that deals with the relationship of organism to each other and its surroundings.this includes the biotic and abiotic interactions .
2. Population growth is mainly influenced by four factors, they are

• Natality- the number of births during a given period in the population that are added to the initial density. Increased natality increases population growth rate.
• Mortality- number of death in a population in a given period is called mortality. mortality decreases population growth.
• Immigration-is the number of individual of the same species that have come into the habitat from elsewhere during the time period under consideration. it increases population growth.
• Emigration-The number of individual left the habitat and gone elsewhere during a period from a population. It decreases population growth

3. i) mutualism- in this interaction both organisms get benefits,. Eg ; pollination is the best example where flower get pollinated and agents get food as nector. It is a +/+ interaction.

ii) Commensalism- in this relation one organism get benefit, but the other organism neither benefited nor harmed.eg:The clown fish and sea anemone . clown fish hide from enemies with in the stinging tentacles of anemone.it is +/0 interaction.

iii) Parasitism- in this one get benefit from the expense of another . one is harmed .For eg; fleas and ticks of dogs. It is a +/- interaction.

4. i) there must be a consistant supply of energy-it is the main raw material of production , in the absence energy supply the ecosystem stability declined.

ii) Autotropic living organisms- they can utilise the energy and utilize in the production of organic compounds.

iii)recycling of material between organism and environment.

   Ecosystem also well balanced when producers, consumers and decomposers are in good relation.