1. What is being studies in ecology?
It is the study of the interactive relationship between organisms, and between organisms and their environment.
2. What are the levels of organization in ecological studies?
(1) species
(2) population
(3) Community
(4) Ecosystem
(5) Biome
(6) Biosphere
3. What is population?
A group of organisms of the same species living in the same habitat.
4. What is being study in ecology at the species level?
Study how individuals of a species adapt to their environment.
5. What is being studied in ecology at the population level?
Study how environmental factors affect the size of a population.
6. What is being studied in ecology at the community level?
Study the interaction among different species in a habitat.
7. How can we define a mature ecosystem?
(1) self-supporting
(2) stable
(3) dynamic
8. What are the three basic features of an ecosystem? (i.e. the main thing being studied during ecological studies.)
(1) Interactions of organisms with one another and with the physical environment
(2) Flow of energy
(3) Cycling of materials
9. What are the abiotic factors of an ecosystem?
(1) temperature
(2) light
(3) rainfall and humidity
(4) wind speed
(5) water current
(6) salinity
(7) Oxygen concentration
(8) Soil properties
10. What is niche?
A niche is the role that an organism plays in its environment. (i.e. its way of life)
11. What is the factors affecting the niche of a species?
The niche of a species is affected by
(1) the temperature range required
(2) the food required and
(3) the space required
by the species.
12. What are the factors affecting species diversity?
(1) species richness (e.g. the number of species)
(2) relative abundance of different species
13. What is dominant species?
It is the species which is found to be of the greatest number in a community. It is the species which exerts the greatest influence in the determination the presence of other species in a community.
14. What type of interaction can be found within a community?
(1) predation
(2) competition
(3) Symbiosis (commensalism, mutualism and parasitism)
15. What is ecological succession?
The changing process of the variety of species(composition) in a community over a period of time is called ecological succession.
17. Describe the process of primary succession.
It starts with barren rock (rocks not covered by soil or vegetation).
(1) spores of lichen (fungi and algae) floating in the air lands onto the rock and start to grow.
(2) They become the pioneer community. Soon a thin layer of soil is formed.
(3) Mosses, ferns and grass start to grow on the rock. They soon become the dominant species and provide food for plant-eating animals.
(4) The dead animal and plants decompose to become humus. Humus makes the soil fertile. Soil becomes thicker and thicker.
(5) Shrubs now start to grow over the grass and ferns and become the dominant species providing more food for more aninals.
(6) The soil continues to thicken. Growth of trees can be supported and soon tree becomes the dominant species. The whole habitat becomes a woodland
(7) Finally, a stable climax community is reached.
18. What is secondary succession?
It takes place on lands where there is vegetation previously.
19. What is the differences between secondary succession and primary succession?
(1) Pioneer community consists of grass and fern instead of lichen
(2) develops more quickly
20. How does energy flow in an ecosystem?
- For most ecosystem, energy ultimately comes from the sun,
- Light energy is changed to chemical energy by plant when they carry out photosynthesis. The chemical energy is stored in the organic matters in the body.
- Energy is transferred to animals when the animals feed on the plants.
- Energy is transferred to different animals when the animals are eaten by other animals.
- During the process of energy transfer, energy is lost to the environment through excretion, through egestion, in form of uneaten body parts of dead organisms and as heat in respiration.
21. What does a food chain shows?
It shows the feeding relationship. It also shows the direction of energy and material flow.
22. What are the different characters in a food chain?
(1) producers
(2) primary consumers
(3) secondary consumers
(4) tertiary consumers
(5) decomposers
23. What is the significance of decomposers in the ecosystem?
Convert the organic substances from the dead remains of producers and consumers, faeces and excretory products into inorganic nutrients so that materials can be absorbed into producers and be recycled.
24. In general, what kinds of living things are decomposers?
(1) fungi
(2) bacteria
25. What is food web?
A network that is formed from a many different food chains.
26. That is trophic level?
Every level in a food chain is called a trophic level.
27. What is the function of a ecological pyramid?
It shows the energy content of each trophic level.
28. What are the two kinds of ecological pyramids?
(1) pyramid of number
(2) pyramid of biomass (dry mass)
29. What is the limitation of ecological pyramids?
(1) Different organisms occupy a different trophic level in different ecosystem.
(2) It does not include the energy that is transferred to decomposers.
30. What are the major processes in the carbon cycle?
(1) the transfer of carbon between trophic levels and decomposers.
(2) the entry of carbon dioxide into the atmosphere and the oceans
(3) carbon fixation
31. What are the three main parts of the nitrogen cycle?
(1) nitrogen in the air
(2) nitrogen in the soil
(3) nitrogen transfer between organisms.
32. How can nitrogen gas enter the living body?
(1) Nitrogen gas in the air is turned into nitrate through processes such as lightning. Together with rain it is brought to the soil and absorbed and assimilated by plants.
(2) The nitrogen fixing bacteria in the root nodules of leguminous plants convert nitrogen gas into ammonium compounds, which is then absorbed into plants.
33. What are the forms of which nitrogen is found in the soil?
In form of
Ammonium compound
Nitrite
Nitrate
34. What is a quadrat?
A quadrat is a fixed square used to measure the abundance of the plants living in a habitat, as well as that of immobile or slow moving animals.