Topic 4 Flashcards
Outline the criteria that should be used to assess whether a group of organisms is a species
Organisms can potentially interbreed to produce fertile offspring. They will have the same type of chromosomes which means similar traits and the same number of chromosomes.
Explain the movement of energy and inorganic nutrients in an eco system
Autotrophs obtain inorganic nutrients from the abiotic environment. Energy is provided mainly by sunlight. Light energy is converted to chemical energy through photosynthesis. Photosynthesis converts inorganic CO2 and water into organic carbon compounds. These carbon compounds are a source of useable energy for life. Carbon compounds are transferred along the food chains when eaten by heterotrophs. Respiration returns CO2 to the environment and releases chemical energy as ATP. ATP is used to carry out life functions. Energy is lost. Nutrients are recycled. Decomposers recycle inorganic nutrients.
Describe how detritivores obtain nutrition and the effects they have in ecosystems
Detritivores obtain nutrition from dead bodies and they are heterotrophic. They clean up the ecosystem. They facilitate further decomposition and contribute to the supply of inorganic nutrients for autotrophs.
Outline the features of ecosystems that make them sustainable
They recycle nutrients, such as carbon. Decomposers break down organic matter. Energy is lost from ecosystems as heat. Energy flow along food chains through trophic levels. Autotrophs supply the food that supports primary consumers. Oxygen for aerobic respiration is released through photosynthesis. CO2 for photosynthesis released by respiration. Populations limited by food supply. Supplies of water from rainfall.
Explain the movement of energy and inorganic nutrients in an ecosystem
Producers obtain inorganic nutrients from the abiotic environment. Energy is provided mainly by sunlight. Light energy is converted to chemical energy through photosynthesis. Photosynthesis converts inorganic CO2 and water into organic carbon compounds. Carbon compounds are a source of useable energy for life. Carbon compounds are transferred along food chains when eaten by consumers. Respiration returns CO2 to the environment and releases chemical energy as ATP. ATP is used to carry out life functions. Energy is lost. Nutrients are recycled and decomposers recycle inorganic nutrients.
Outline energy flow through a food chain
energy from the sun is converted to chemical energy by photosynthesis. Chemical energy flows through the food chain by feeding. energy is released from carbon compounds by respiration. Heat is not recyclable. Energy is lost in excretion. Energy losses between trophic levels limits the length of food chains.
Describe the reasons for the shape of a pyramid of energy
Pyramid of energy has a stepped shape with the largest bottom step being producers, then first consumers, second consumers, etc. Light energy from the sun is converted to chemical energy in carbon compounds by photosynthesis. Energy released by respiration is used in living organisms and converted to heat. Heat energy is lost from ecosystems. Energy is also lost as excretion.
Explain the processes by which energy enters and flows through ecosystems
Light energy is the initial energy source for all organisms. Producers convert light energy to chemical energy by photosynthesis producing carbohydrates. Organic carbon compounds used for energy. Energy is passed as food along the food chains. Cellular respiration releases energy as ATP from food. Energy is lost as heat. Energy is lost at each tropic level. Energy is not recycled.
Describe how energy flows through and is used by organisms in ecosystems
Producers obtain energy from light. Energy passed in the form of food. Consumers obtain energy from other organisms. Energy is released by cell respiration. ATP is produced.
Outline how the energy flow through food chains limits their length
only a small proportion of energy passes from one trophic level to the next. energy is released by respiration and lost as heat. energy losses due to uneaten parts. more energy available if feeding at an earlier stage in a food chain.
Explain the transformation of carbon compounds in the carbon cycle
Producers convert CO2 into carbon compounds in photosynthesis. CO2 diffuse from the atmosphere into plants. Carbon compounds are transferred through food chains. CO2 produced by respiration diffuses out of organisms into the atmosphere. Decomposers release CO2 during decay. Methane is produced from organic matter in anaerobic conditions. Some methane diffuses into the atmosphere. Methane is oxidized to CO2 and water in the atmosphere. Peat forms when organic matter is not fully decomposed because of anaerobic conditions in waterlogged soils.
Explain the cycling of carbon in an ecosystem
producers absorb CO2 from the atmosphere. autotrophs make carbohydrates. carbon compounds pass along food chains. respiration releases CO2 into the atmosphere. CO2 is released by decomposition. methane is produced during anaerobic respiration of organic matter. methane is oxidized into CO2 in the atmosphere. Pear is made from partially decomposed organic matter. combustion of biomass releases CO2 into the atmosphere.
Outline the roles bacteria play in the carbon cycle
decomposition of dead organic material by saprotrophic bacteria. decomposition leads to CO2 regeneration due to respiration. saprotrophic bacteria only partially decompose dead organic matter in anaerobic conditions in waterlogged soil. This results in peat formation in swamps. Photosynthetic bacteria fix CO2 in photosynthesis.
Discuss the relationship between atmospheric CO2 concentration and global temperatures
Greenhouse effect keeps Earth warm. Over time Earths temp has fluctuated naturally. Changes in human activity has led to increased CO2 concentrations. CO2 absorbs long-wave radiation, trapping heat. Increased atmospheric CO2 concentrations correlates with increased global average temperature. Use of fossil fuels increased atmospheric CO2. Deforestation causes less CO2 to be absorbed.
Outline how greenhouse gases interact with radiation and contribute to global warming.
CO2 is a greenhouse gas and so are methane, nitrogen oxide and water vapor. Sunlight passed through the atmosphere. Greenhouse gases absorb some radiation and heat emitted by the Earths surface. Greenhouse gases allow short wave radiation to pass through the atmosphere but absorb long wave radiation. Sunlight is mostly short wave.
