What do the arrows in food chains indicate?
The arrows on the food chain indicate where the energy is passed. For example, and arrow pointing from grass to a cow illustrates that cows eat the grass and therefor recieve their energy from the grass. It basically represents the energy flow form one ecosystem to another (the grass ad cow)
Term Definitions
ProducerA food chain always starts with a producer, which is an
organism that makes food. This is usually a green plant, because plants can make their own food by photosynthesis. They are called producers because they produce their own foods. |
ConsumerConsumers are those that eat the producer or any other animals in the food chain. They are always animals. For example, If a cow eats the grass, the cow is the consumer and the grass is a producer.
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HerbivoreA herbivore is an animal that feeds on plants only.
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CarnivoreA carnivore is an animal that feeds on other animals. A carnivore does not eat plants but meat.
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Food WebA Food web is a system of interlocking and interdependent food chains.
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What type of organism occupies the lowest trophic level in a food web?
The trophic level of an organisim is the position it occupies in a food chain.
Food chains start at trophic level 1 with primary producers such as plants. Only a small portion of the energy stored in the organisms of a trophic level ends up being stored in the organisms that make up the next trophic level. What happens to the remaining energy? |
Producers use about 90% of the food energy they produce for their own life processes, so the animals that eat these produces only get approximently 10% of the energy made by the producer. This means that the producer uses 90% of the food they eat for their own personal needs. Animals that eat the producers will only get 10% of this energy. The 90% of the energy an animal eats or plant produces they use for many different reasons. Some of it goes to heat--when an animal use their
muscles, it produces heat, for example, warm blooded animals are constantly using energy to keep at the right temperature.Even plants can produce heat! Some of it goes to potential energy, energy stored in the chemical bonds of the body of the plant or animal--some of that energy can be released when wood is burned, for instance. In some cases an animal can not digest all of the bonds in its meal, excreting the undigested mass. Other things such as bacteria can then digest
some of the remaining food and use that energy for its activities.
muscles, it produces heat, for example, warm blooded animals are constantly using energy to keep at the right temperature.Even plants can produce heat! Some of it goes to potential energy, energy stored in the chemical bonds of the body of the plant or animal--some of that energy can be released when wood is burned, for instance. In some cases an animal can not digest all of the bonds in its meal, excreting the undigested mass. Other things such as bacteria can then digest
some of the remaining food and use that energy for its activities.
Some people choose to be vegetarian out of concern for the environment. Why does eating large quantities of meat rather than plant matter not as environmentally friendly as a plant-based diet?
We humans eat about 230m tonnes of animals a year. We mostly consume and breed four species – chickens, cows, sheep and pigs – all
of which need large amounts of water and food, produce methane and other greenhouse gases and pleave mountains of physical waste. This is harmful for the environment. Last year, a Food Climate Research Network report found that meat and dairy consumption in the United Kingdom's alone consumption was responsible for 8% of the country's total greenhouse gas emissions. Eat a steak or a chicken and you are effectively consuming the water that the animal has needed to live and grow. Vegetarian author John Robbins calculates it takes 60, 108, 168, and 229 pounds of water to produce one pound of potatoes, wheat, maize and rice respectively. But a pound of beef needs around 9,000 litres – or more than 20,000lbs of water.That is an extremely signifigant difference.
of which need large amounts of water and food, produce methane and other greenhouse gases and pleave mountains of physical waste. This is harmful for the environment. Last year, a Food Climate Research Network report found that meat and dairy consumption in the United Kingdom's alone consumption was responsible for 8% of the country's total greenhouse gas emissions. Eat a steak or a chicken and you are effectively consuming the water that the animal has needed to live and grow. Vegetarian author John Robbins calculates it takes 60, 108, 168, and 229 pounds of water to produce one pound of potatoes, wheat, maize and rice respectively. But a pound of beef needs around 9,000 litres – or more than 20,000lbs of water.That is an extremely signifigant difference.
What would happen if one or more of the components of the food web were eliminated?
If one or more animals of a food chain are eliminated, it would effect on specific organisms or even the entire ecosystem. Animals who dont have a large variety of foods would be the most effected if their food source were to be eliminated. The animals would either need to adjust their diet of risk extiniction. But there are few animals that prey on one organis. In reference to the food web to the left of the page, if the squirels were to become extinct it's predators would be only slightly affected because they have other sources of food, but this leads to more stress for the other organisms as their predatores now require more of the to make-up for their faction of squriel's in their diet. This cpuld put pressure on the animals being consumed and decrease their population which again could lead to the extinction of these animals. The deer on the page only has one food source. If that was eliminated, it would either need to adapt and find another food source to prevent extinct
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Predict the impact of over-fishing of the large fish on the abundance of sharks, the small fish and crabs.
The over-fishing of large fish will have heavy consequences. It would educe the population of large fish and effect the entire food chain. Large fish eat small fish, if there are less large fish there will be more small fish as they are not being eaten as much. With a rise in small fish population more phytoplankton and algae will be required to feed the small fish. The demand will only rise with the more large. Sharks will have been deprived of their main food source (large fish) and will turn to other organisms to meet their food requirements. They will eat more of the smaller things or in some cases, humans. Moving onwards, with more learge fish to eat, humans may reduce the amount of crabs they catch, which could lead to a population rise.
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