Biology - 9201 OxfordAQA

Decay And The Carbon Cycle

Resumen

Nothing on this planet gets thrown away. A fallen oak leaf, a dead beetle, the shell of an egg, the carbon in your last breath: every one of them is on loan. Give it long enough and the same atoms turn up again inside a root, a seed, a fish or a person. Ecosystems do not run on fresh supplies of matter, because there are none. They run on the same finite stock of elements, used and returned and used again.

This lesson follows one element, carbon, all the way round that loop. You will see how a leaf traps it, how a food chain passes it on, and how three separate routes send it back to the air: the respiration of plants and animals, the feeding of the microorganisms that rot dead material, and the burning of wood and fossil fuels. You will also learn the conditions that make decay fast or slow, why gardeners turn a compost heap, and why energy alone refuses to go round with the matter.

Objetivos

  1. Living organisms remove materials from the environment for growth and other processes. These materials are returned to the environment either in waste materials or when living things die and decay.
  2. Materials decay because they are broken down (digested) by microorganisms. Microorganisms are more active and digest materials faster in warm, moist, aerobic conditions.
  3. The decay process releases substances that plants need to grow.
  4. In a stable community, the processes that remove materials are balanced by processes that return materials. The materials are part of a constant cycle.
  5. The constant cycling of carbon is called the carbon cycle. In the carbon cycle: carbon dioxide is removed from the environment by green plants and algae during photosynthesis; the carbon from the carbon dioxide is used to make carbohydrates, fats and proteins, which make up the body of plants and algae; when green plants and algae respire, some of this carbon becomes carbon dioxide and is released into the atmosphere; when green plants and algae are eaten by animals and these animals are eaten by other animals, some of the carbon becomes part of the fats and proteins that make up the bodies of the consumers; when animals respire, some of this carbon becomes carbon dioxide and is released into the atmosphere; when plants, algae and animals die, some animals and microorganisms feed on their bodies; carbon is released into the atmosphere as carbon dioxide when microorganisms respire; by the time the microorganisms and detritus feeders have broken down the waste products and dead bodies of organisms in ecosystems and cycled the materials as plant nutrients, all the energy originally absorbed by green plants and algae has been transferred; combustion of wood and fossil fuels releases carbon dioxide into the atmosphere. Students should be able to apply the principles of the carbon cycle.

Mapa mental

Este tema esta esquematizado para ver como se conectan las ideas.

Abre el mapa mental en la app

Nota de la lección

Weigh a woodland in autumn and it looks like a system throwing material away. Tonnes of leaves drop, animals die, birds leave droppings on every branch. Come back the following summer and the woodland floor is not buried under a year of litter; it is bare enough to walk on, and the trees above it are heavier than they were. Something has taken the discarded material apart and handed the pieces back to the trees. That process is decay, and it is the reason an ecosystem can keep running for centuries without ever importing new matter.

Apunte completo disponible en la aplicacion Green Bridge

Instala la aplicacion Green Bridge CBT en tu movil u ordenador para acceder a toda la biblioteca IGCSE: examenes anteriores, criterios de correccion, mapas mentales, tarjetas de estudio y lecciones en audio.

Notas de lección completas con diagramas
Asistente de aprendizaje con IA
Simulacros cronometrados que se corrigen en cuanto terminas
Disponible en Android, Windows, macOS y Linux App para iOS proximamente

Evaluación de la lección

Felicitaciones por completar la lección del Decay And The Carbon Cycle. Ahora que has explorado el conceptos e ideas clave, es hora de poner a prueba tus conocimientos. Esta sección ofrece una variedad de prácticas Preguntas diseñadas para reforzar su comprensión y ayudarle a evaluar su comprensión del material.

Te encontrarás con una variedad de tipos de preguntas, incluyendo preguntas de opción múltiple, preguntas de respuesta corta y preguntas de ensayo. Cada pregunta está cuidadosamente diseñada para evaluar diferentes aspectos de tu conocimiento y habilidades de pensamiento crítico.

Utiliza esta sección de evaluación como una oportunidad para reforzar tu comprensión del tema e identificar cualquier área en la que puedas necesitar un estudio adicional. No te desanimes por los desafíos que encuentres; en su lugar, míralos como oportunidades para el crecimiento y la mejora.

  1. Which group of organisms is mainly responsible for the decay of dead material? A. Producers B. Herbivores C. Microorganisms such as bacteria and fungi D. Carnivores Answer: C
  2. Which combination of conditions gives the fastest rate of decay? A. Cold, dry and aerobic B. Warm, moist and aerobic C. Warm, dry and anaerobic D. Cold, moist and anaerobic Answer: B
  3. In the carbon cycle, which process takes carbon dioxide out of the atmosphere? A. Respiration B. Combustion C. Decay D. Photosynthesis Answer: D
  4. Which statement about the carbon cycle is correct? A. Only animals return carbon dioxide to the atmosphere B. Plants, animals and microorganisms all return carbon dioxide by respiration C. Carbon dioxide is returned to the atmosphere only when fuels are burned D. Decomposers remove carbon dioxide from the atmosphere Answer: B
  5. A pile of dead leaves has a mass of 250 g. After 40 days its mass is 90 g. What percentage of the original mass has been lost? A. 36% B. 44% C. 64% D. 160% Answer: C

Resuelve estas preguntas en la aplicacion

Resuelve estas preguntas en la aplicacion

Practica preguntas simuladas

¿Quieres practicar preguntas simuladas sobre Decay And The Carbon Cycle? Descarga la aplicación Green Bridge CBT para acceder a preguntas simuladas y evaluaciones completas sobre este tema.

Descarga la aplicación en Google Playstore.

Todo lo que necesitas para destacar en JAMB, WAEC y NECO.

Green Bridge CBT Mobile App
Asistente de Chat de Aprendizaje Personalizado con IA
Más de 200.000 preguntas de examen de IGCSE, JAMB, WAEC y NECO.
Más de 1200 notas de lecciones
Soporte sin conexión: Aprende en cualquier momento y lugar.
Horario del Puente Verde
Resúmenes de Literatura y Preguntas Potenciales
Controla tu rendimiento y progreso.
Explicaciones detalladas para un aprendizaje integral