Science Review October 10 PDF

Plants and the Ecosystem Plants provide shelter and food for organisms Plants use photosynthesis to make oxygen and food Produce oxygen Plants store or use carbon dioxide Clean up pollution Wetlands Areas of water with swampy, bullrushes Usually areas with beavers Filter water Store pollut...

Plants and the Ecosystem Plants provide shelter and food for organisms Plants use photosynthesis to make oxygen and food Produce oxygen Plants store or use carbon dioxide Clean up pollution Wetlands Areas of water with swampy, bullrushes Usually areas with beavers Filter water Store pollution Provide habitats for organisms The beaver is a keystone species because it creates the habitat for all organisms Trees store carbon Take carbon in through their leaves Store carbon in their roots and in fibres in trees Relationships in Ecosystems Mutualism (animals help each other) Commensalism (one animal lives with another but only one animal is helped) Parasitism (when an organism lives on or in another organism and eventually kills it) Bioaccumulation and Biomagnification Bioaccumulation is when nutrients or energy builds up in an organism BUT it is also when toxins build up in your body Biomagnification is when more and more toxins build up in a food chain. The consumer at the top of the food chain gets most of the toxin. Biodiversity All the living organisms on earth Why is it important to have biodiversity ? The greater the variety of life , the greater the chance of survival as environments change Example: Living organisms need to have diversity in order to adapt and change with conditions on earth. Organisms need to have variation. There needs to be both Interspecies(between species) variation and Intraspecies (within the same species) variation. Deforestation We are losing trees at a very high rate due to factors such as: 1. Using land for farming 2. Building industry 3. Building roads 4. Mining activity Deforestation causes: Destruction of habitats Less oxygen being produced More carbon dioxide in atmosphere Less biodiversity (organisms and plants disappearing) Succession Succession refers to the gradual process where a community of organisms evolves over time following a disturbance, leading to a stable, mature community. Example: A forest fire destroys most of an area’s plants. New plants naturally grow and eventually a new ecosystem forms. Primary succession is the beginning step of ecological succession where species known as pioneer species colonize an uninhabited site, which usually occurs in an environment with little or no vegetation and other organisms. How Fire Can Restore a Forest: A Time-Lapse (Ground View) Secondary succession It starts with pioneer species coming into the cleared area, and over many years, they make way for a community of intermediate species, and finally a stable climax community form.