生物与其周围环境之间的关系英文版.ppt

1、,Introduction,Habitat: the place where an organism occurs Population: a group of organisms of the same species in an area Community: all population & plants in the same area,Introduction,Ecosystem: a stable, self-supporting system which consists of communities interacting with each other Ecology: th

2、e study of the interactions between living organisms & their environment,Different Habitats,Freshwater Pond,Freshwater Stream,Grassland,Different Habitats,Mangrove,Rocky Shore,Coral Reef,What is Environment ?,Composed of 2 components, Physical Factors & Biotic Factors, which influence the lives of o

3、rganisms,Temperature Light Rainfall & Humidity Wind Speed Soil (esp. for plants) pH,Physical Factors,Biotic Factors,Consists of all the other organisms living together in the same habitat,Energy Flow within an Ecosystem,SUN,Producers,Primary Consumers,Secondary Consumers,Tertiary Consumers,DECOMPOSI

4、TION,HEAT,Respiration,Dead remains, excreta, etc,Food Chain / Food Web,shows the feeding relationship between organisms,green plants,rabbit,snake,hawk,grasshopper,lizard,toad,Decomposers,not shown in food chain consist of Bacteria & Fungi break down organic wastes & dead bodies of other organisms to

5、 simpler compounds which are then absorbed by green plants significance: enable the recycling of materials within an ecosystem,Trophic Level,Organism,Type,Pyramids of Numbers(Examples),Producers,Primary Consumers,Secondary Consumers,Tertiary Consumers,Pyramids of Biomass,500,Producers,Primary Consum

6、ers,Secondary Consumers,50,1,Why is there energy loss ? Uneaten food Respiration Egestion & Excretion solving the food problem by consuming organisms in lower trophic levels down a level, increase at least 10 times of food available,Energy Lost up a Food Chain,Pyramids of Biomass,Biomass is the tota

7、l dry mass of organisms at a trophic level,Effects of DDT,DDT is an effective pesticide DDT has been used for about 20 years It had been banned for over 20 years But, nowadays, the body of every people still has DDT,Effects of DDT,Reasons : it has excessively long degeneration period (it requires te

8、ns of years) it is not easy be destroyed by metabolism of living organisms, so it is easily accumulated along the food chain It killed many predatory birds due to its accumulation to high concentration through the food chain,DDT Accumulation,Carbon Cycle,Carbon dioxide in air,organic substances in p

9、lants,organic substances in animals,absorption & photosynthesis,respiration,fossil,feeding,respiration,burning,incomplete decomposition,Nitrogen Cycle,nitrate in soil,protein in plants,protein in animals,ammonia,nitrogen in air,absorption & photosynthesis,feeding,putrefying bacteria (decomposition),

10、faeces, urine, dead body,nitrifying bacteria (nitrification),denitrifying bacteria (denitrification),nitrogen- fixing bacteria,Investigation 23.1,Investigation of a Balanced Aquarium,Why is it necessary to use tap water which has been standing for a few day ?,Ans: Because fresh tap water contains ch

11、lorine which is harmful to organisms in the aquarium.,Why is it unsuitable to introduce large carnivores into the glass jar ?,Ans: Because they require more food to survive and they will eat up all the organisms in the aquarium.,Describe the appearance of the water snails and the freshwater plants a

12、fter a few days if the aquarium is balanced ?,Ans: The water snails and the aquatic plants will remain healthy even after a few weeks.,What will happen to the aquarium if it is placed in darkness all the time ? Why ?,Ans: Both the water snails and the freshwater plants will gradually die since there

13、 is no light for the aquatic plants to carry out photosynthesis to make food,What will happen to the aquarium if it is placed in darkness all the time ? Why ?,Ans: so the plants cannot survive without food supply. As all aquatic plants died, the water snails also die due to starvation.,Ecological In

14、dependence of Organisms,Predation (Predator-prey relation),Time,Number,prey,predator,Hare,Lynx,Time,Number,Competition (competitors),the winner,the loser,Cuckoo displacing the hosts egg,Ecological Independence of Organisms,Commensalism,one gets (physical) benefit, one feels no effect organism benefi

15、ted: Commensal organism with no effect: Host easy separate from each other eg. barnacle on crab (barnacle gets transport),both obtain benefits not easy separate (even cannot be separated) e.g.1. lichen (mutualism of specific algae & fungi) fungi absorb moisture from air and moist the algae algae provide carbohydrates for the fungi,Mutualism,e.g.2. Nitrogen-Fixing Bacteria & Leguminous Plants bacteria fi