Objective Three: The Interdependence of Organisms and the Environment (Biology)
Plants have three organ systems• Roots: absorb water and mineral, and anchors plants to the ground• Stem: supports leaves and branches • Xylem and Phloem run like a plumbing system through the stem and connects roots to the leaves• Leaves: main organs of plants that conduct photosynthesis: • intercepts sunlight, captures carbon dioxide, and stores energy in the form of glucose • releases oxygen into the air in a process called transpiration
• The chloroplast in plants use the energy in sunlight to make a sugar called glucose. Plants energy from glucose.• Animals get energy from eating plants or eating animals that eat plants. • The process by which cells break down glucose (a sugar) to produce energy
• Population: a group of organisms that belong to the same species• Species: a group of organisms that are capable of interbreeding and producing fertile offspring
webs, arrows always● The feeding relationships in an ecosystem can be shown in a Energy ﬂows in one direction through an ecosystem. Green plants point from the organism food web, which consists of many interconnected food chains. convert the sun’s energy to food energy (potential chemical energy). that is consumed to the● All food chains and food webs begin with producers. consumer. Arrows show the plants are the next step. These animals are eaten Animals that eat by other animals. At each level in a food chain, consumers convert the flow of matter and● Energy moves through ecosystems in food chains and food webs energy. food energy to mechanical energy, which is used for activities some every time an organism eats another organism. such as running and breathing. However, much of the energy stored in● • An interactive systemRemember! includes the physical environment Energy cannot be recycled. that food is used for metabolic processes, such as maintaining a constant body temperature. and the organismsMetabolismWeb to all theretransferredabout 10 percent ofInthe energy atfor instance, nearly half of thatrefers chemical live theFood reactions Partial African Grassland In fact, only is to the next level. mammals, any level in a food chain that take place in an the energy obtained from food is lost to the environment as heat. This organism. is why there are usually only four levels in a food chain. Only rarely Scavengers is there enough energy available to support a ﬁfth level. An energy Vultures pyramid shows the relative amount of energy available at each level. Carnivores Lions Cheetahs Energy Pyramid Herbivores Carnivores that eat carnivores Zebras Baboons Impalas Giraffes Producers Grasses Acacia trees Carnivores that eat herbivores Decomposers Fungi Bacteria HerbivoresThis grassland food web is made up of producers, consumers (herbivores,carnivores, and scavengers), and decomposers. Scavengers such asvultures feed on the remains of dead animals. Decomposers such as Producersbacteria and fungi decompose dead organisms and their wastes. 45 An energy pyramid shows the energy stored at each trophic (feeding) level in an ecosystem.