Biology

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  • Created by: Emma
  • Created on: 15-05-11 17:18

Pyramids of Biomass

Light energy pours out continually onto the surface of the Earth. Green plants capture a small part of this light energy by chlorophyll. Biomass is the mass of living material in an animal or plant. Biomass is often measured as the dry mass of biological material in grams.

The energy in the Biomass made by plants is passed through food chains or food webs into the animals which each plants. NO matter how long the food chain or complex the food web the SUN is always the original source of biomass.

If you count the number of organisms at each level you will be able to compare them, you show this using a pyramid of numbers.

A pyramid of Biomass should always be in a shape of a pyramid unlike the pyramid of numbers which will most probably look nothing like one. If you are putting a food chain into a pyramid of Biomass it should go in this order:

  • Biomass of tertiary consumer (carnivore)
  • Biomass of secondary consumer (carnivore)
  • Biomass of primary Consumer (herbivore)
  • Biomass of Plants
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Energy Losses

Energy loss in waste - The biomass which an animal eats is a source of energy but not all of the energy can be used. Herbivores cannot digest all of their plant material so instead it passes out of the body in the faeces. Carnivores also cannot digest everything so passes out of the body by faeces.

If and animal has too much protein it will be broken down and then would be passed out of the body by urine.

Energy loss due to movement - Movement uses a great deal of energy, the muscles use energy to contract so the more and animal moves about the more energy it uses from its food. The muscles produce heat as they contract.

Keeping a constant body temperature - Heat losses are particularly large in mammals and birds because they are 'warm-blooded' this means that their body temperature will always stay the same no matter what their surrounding temperature is. Although, they still use up energy by trying to either cool down or warm up. 'Warm-blooded' animals need more energy compared to 'cold-blooded' animals so they will eat more.

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Energy in food production

Food chains in food productions - In the development world much of our diet consists of meat or other animal products such as eggs. The meats that we eat will eat plants but by the time the food gets to us the energy from the plant would have been all used up. There is only a limited amount of the Earth's surface that we can use to grow food.

Artificially managed food production - Farmers want the best meat and because of this they try to restrict the animals. For example:

  • Limiting the movement of food animals, they do this because then the animal will not use as much energy up because of movement, instead they would use it to grow they will also be more eat compared to an animal that moves.
  • Controlling the temperature of their surroundings, this again will prevent the animal losing energy, they will not have to try to cool down or warm up instead they will be at the correct temperature without having to move around and use their energy up.

By them not moving around as much and not losing as much energy, it will make the food production much more efficient.

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Decay

Living organisms remove materials from the environment as they grow. They return them when they die through the action of the decomposers

Dead materials decay because they are broken down (digested) by microorganisms.

Decomposers work more quickly in warm, moist conditions. They work more quickly than because if it gets too hot the enzymes which controls it they will denature also if it isn’t moist the food will not dissolve so easily and will dry out more quickly. Many of them also need a good supply of oxygen

The decay process releases substances which plants need so they can grow healthy.

In a stable community the process that remove materials (particularly plant growth) are balanced by the processes which return the materials.

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The Carbon Cycle

All the time a relatively small amount of available carbon is cycled between living things and the environment; this is called the Carbon Cycle.

Photosynthesis- Green plants use Carbon dioxide from the atmosphere, they use it to make Carbohydrates which in turn makes biomass. This all then is passed onto to animals as they eat the plants.

Respiration - Animals use oxygen to break down glucose providing energy for their cells. Carbon dioxide is produced as a waste product and then is returned into the atmosphere. Also when plants and animals die their bodies are broken down by decomposers. These then release carbon dioxide into the atmosphere when they respire.

Combustion - Fossil fuels contain Carbon and when they are burned Carbon is released back into the atmosphere and then used.

Respiration - Glucose + Oxygen --> Carbon dioxide +Water (+light energy)

Combustion - Fossil fuels + Oxygen --> Carbon dioxide + water (+Light energy)

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Farming - Intensive or Free Range

There are 2 sides of Intensive and free range here is some points for Chickens for meat and for eggs.

  • Intensive farming Benefits - Lots of chickens in small space, Little or no food wastage, Energy wasted kept to a minimum, Maximum weight and Cheap
  • Intensive Farming Costs - Chickens unable to behave naturally, Large barns need heating and lighting , Chickens legs may break and risk of disease
  • Free range Benefits - Chickens live more naturally, No heating/lighting costs, Less food needs supplying (find it themselves) and can charge more for free range eggs.
  • Free range Costs - Chickens more vulnerable to weather and predators, More land needed, Eggs cannot be collected automatically and fewer eggs lay especially in the winter when cold.

There are also many for Cattle for beef.

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QUESTIONS

Questions - (3.1 - 3.6)

  • What is the source of all the energy in the living things on Earth?
  • What is a pyramid of numbers?
  • What is a pyramid of Biomass?
  • Why is Biomass lost in faeces?
  • What do we mean by 'Warm-blooded' animals?
  • Name 3 animals which we use for food
  • Why would there be more food for everyone if we all ate plants?
  • Which group of organisms take materials out of the soil?
  • Which type of organism are the decomposers?
  • What are the main source of Carbon on earth?
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ANSWERS

Answers:

  • The sun
  • Pyramid of numbers is the amount of animal/plant
  • Pyramid of Biomass is the mass of the animal/plant
  • Biomass is lost in faeces because some animals are able to digest everything so instead it passes by their faeces
  • Warm-blooded animals are animals that will always have to same body temperture even when their surroundings is completly different.
  • Goat, Cow and Pig
  • Because if we ate plants directly we would have more energy
  • decomposers
  • Microogranisms
  • The ocean
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