https://www.khanacademy.org/science/grade-7-science-cambridge-curriculum/x754b285620daf71e:ecosystems/x754b285620daf71e:populations-communities-and-ecosystems/v/ecosystems 2026-04-30T07:30:36.209464894Z Ecosystems Ecosystem Khan Academy Pakistan video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Ecosystems Ecosystem https://cdn.kastatic.org/ka-youtube-converted/RO5xwD1zNDg.mp4/RO5xwD1zNDg.mp4 290 Populations, communities and ecosystems https://www.khanacademy.org/science/biology/ecology/intro-to-ecosystems/v/ecosystems-and-biomes 2024-05-06T19:22:43.24334365Z Ecosystems and biomes Ecosystems, made up of living and non-living things, can be as small as a tide pool or as big as a rainforest. Ecosystems can be classified as terrestrial or aquatic, with aquatic further divided into marine and freshwater. Land ecosystems are often categorized into biomes, such as tropical forests or deserts, based on climate and vegetation. Sal Khan video https://cdn.kastatic.org/googleusercontent/K2QpBE0ntylRvNCVAHvhZrURodOjkNXBGCQXwIVImX6lzX57dEnq4diEcjfrAJHwk0xlwyWB2nyLDRsrAZWWzZbE Ecosystems and biomes Ecosystems, made up of living and non-living things, can be as small as a tide pool or as big as a rainforest. Ecosystems can be classified as terrestrial or aquatic, with aquatic further divided into marine and freshwater. Land ecosystems are often categorized into biomes, such as tropical forests or deserts, based on climate and vegetation. https://cdn.kastatic.org/ka-youtube-converted/A495e31cDdE.mp4/A495e31cDdE.mp4 453 Populations, communities and ecosystems https://www.khanacademy.org/science/ms-biology/x0c5bb03129646fd6:interactions-in-ecosystems/x0c5bb03129646fd6:populations-communities-and-ecosystems/e/apply-populations-communities-and-ecosystems 2026-04-26T16:30:39.382257956Z Apply: Populations, communities, and ecosystems Apply your understanding of populations, communities, and ecosystems in this set of free practice questions aligned to NGSS standards. Khan Academy exercise https://www.khanacademy.org/science/biology/ecology/intro-to-ecosystems/a/what-is-an-ecosystem 2025-06-30T13:17:39.587845569Z What is an ecosystem? Learn what an ecosystem is, how energy and matter move through ecosystems, and what makes an ecosystem stable. article https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:ecology-and-natural-systems/x230b3ff252126bb6:organization-of-natural-systems/v/biotic-and-abiotic-factors-in-earths-natural-systems 2024-05-28T21:41:02.467178644Z Biotic and abiotic factors in Earth’s natural systems Natural systems are made up of both biotic factors (living organisms and their interactions) and abiotic factors (non-living parts of the environment such as sunlight and temperature). Earth can be divided into four systems, called spheres: the atmosphere (gases surrounding Earth), the biosphere (all living organisms), the geosphere (Earth's interior and surface), and the hydrosphere (all forms of water). Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/1b8f7160-2496-44ec-8a88-7e34c7fc5c26_1280_720_base.png Biotic and abiotic factors in Earth’s natural systems Natural systems are made up of both biotic factors (living organisms and their interactions) and abiotic factors (non-living parts of the environment such as sunlight and temperature). Earth can be divided into four systems, called spheres: the atmosphere (gases surrounding Earth), the biosphere (all living organisms), the geosphere (Earth's interior and surface), and the hydrosphere (all forms of water). https://cdn.kastatic.org/ka-youtube-converted/GxKWCiZHsvo.mp4/GxKWCiZHsvo.mp4 314 Populations, communities and ecosystems https://www.khanacademy.org/science/ms-biology/x0c5bb03129646fd6:interactions-in-ecosystems/x0c5bb03129646fd6:populations-communities-and-ecosystems/v/ms-populations-communities-and-ecosystems 2022-10-21T22:40:33.613234713Z Populations, communities, and ecosystems Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/5672b967-c8cc-46f0-ba8b-431eb788378e_1280_720_base.png Populations, communities, and ecosystems Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. https://cdn.kastatic.org/ka-youtube-converted/xzINev2Bd8s.mp4/xzINev2Bd8s.mp4 226 Populations, communities and ecosystems https://www.khanacademy.org/science/ap-biology/ecology-ap/disruptions-to-ecosystems/a/hs-human-impact-on-ecosystems-review 2021-04-29T08:01:14Z Human impact on ecosystems review article https://www.khanacademy.org/science/revision-term-2-tg-biology-class-8/x04828215b460a495:week-1/x04828215b460a495:different-ecosystems/e/interactions-among-organisms 2026-04-07T23:55:07.30621384Z Interactions among organisms Explore how interactions in an ecosystem create benefits such as soil protection by roots, oxygen release by plants, cooling and moisture retention under trees, and the role of abiotic–abiotic relations like sunlight and wind. This exercise helps Class 8 students identify biotic–abiotic, abiotic–abiotic, and biotic–biotic interactions and understand their importance for ecosystem balance. Yajurva Joshi exercise https://www.khanacademy.org/science/ms-biology/x0c5bb03129646fd6:ecosystems-and-biodiversity/x0c5bb03129646fd6:humans-and-ecosystems/e/apply-humans-and-ecosystems 2026-04-26T16:30:39.382257956Z Apply: Humans and ecosystems Apply your understanding of humans and ecosystems in this set of free practice questions aligned to NGSS standards. Khan Academy exercise