Bio chapter 1

• Bioaccumulated toxins move their way up the food web, including mercury, lead, arsenic, and cadmium
• Mercury gets into fish
• Toxins in the food web increase higher on the food web
• Bioaccumulation is different from Biomagnification
• Complete the following table comparing each type of ecological pyramid


  1. Pyramid of Numbers: is the number of organisms in each tropic level. it can be inverted in a forest ecosystem

  2. Pyramid of Biomass: is the dry mass of living or once living organisms. it can be inverted in the ocean ecosystem.

  3. Pyramid of Energy: is based on the total amount of energy in each tropic level. It can not be inverted
• A food chain shows a linear flow of energy, while a food web is a network of interconnected food chains
• Rachel Carson was important for writing Silent Spring
• Biomagnification is the increase in concentration of a pollutant in a food web
• Seafood has health benefits & risks. Sustainable seafood is generally healthier than conventional seafood
• 5,500 metric tons of mercury are released into the environment
• Ecological pyramids are used to model feeding relationships among trophic levels in an ecosystem
• The top level of a pyramid of biomass is narrower than the lower levels because top-level consumers take into account the size of the ecosystem
• Root web shows a more realistic picture of the ecosystem
• A pyramid of energy consists of 1000 J, 10,000 J, 100,000 J, and 1,000,000 J of sunlight on the total amount of energy in each trophic level
• Decomposers fit into the food chain as part of the ecosystem
• Rule of 10: Only 10% of energy is passed up in a food chain
• According to the second law of thermodynamics, with each conversion of energy, some of the initial energy available is lost as heat
• Energy transfer in the Biosphere

  1. Organisms can be identified by how they obtain their food and the kind of food they eat (producers, herbivores, carnivores, and decomposers)

  2. Organisms can be identified by the type of food-maker or food consumer they are (producers, primary consumers, secondary consumers, tertiary consumers)

  3. Trophic level - the feeding level through which energy or matter travels. The FIRST Trophic level is always producers
• Organisms get their energy from deep within the Ocean through Chemosynthesis
• In the marine food chain, if the carnivore at the fourth trophic level is overfished and the population of this species decreases drastically, it will have an effect on the species found at the other trophic levels
• Decomposers fit into the food chain above the consumers
• Reflective surfaces or thick clouds return a large albedo, while dark surfaces like treetops and water absorb the rays from the sun
• Photosynthesis and Chemosynthesis are essential processes providing energy to organisms
• For species living in anaerobic environments, the energy-releasing process is called Fermentation
• Organisms that can produce their own food are called producers or autotrophs
• Plankton are important because Phytoplankton produce a lot of the gas and Oxygen we need to survive
• Trophic levels


  • Primary producer (plant)
  • Primary consumer (herbivore
  • Secondary consumer (carnivore)
• Producers in the chemosynthetic food web are archaea and chemosynthetic bacteria
• Albedo refers to the amount of energy that is reflected from the sun
• Some products of fermentation are Beer
• Organisms that obtain energy from eating other organisms are called consumers or heterotrophs
• Sulfur Cycle


  Sulfur is cycled through the atmosphere and is an important component of proteins for all organisms
• Sulfur returning to land

  1. acid precipitation

  2. sedimentation
• Forms of sulfur cycled

  • sulfur dioxide (SO₂)
  • sulfate (SO-²)
  • hydrogen sulfide (H₂S)
• Marine animals use phosphate to make their bones and shells
• Phosphorus does not cycle through the atmosphere
• Legumes are plants like soybeans, peas, peanuts, etc., with nodules on their roots where nitrogen-fixing bacteria reside
• Phosphorus moving between organisms, land, and water

  1. weathering

  2. erosion
• Eutrophication is caused by excess nutrients like nitrogen and phosphorus leading to algal growth and death of aquatic life
• The Nitrogen Cycle involves nitrogen fixation