b15 organisms and their environments

what do food chains show

the transfer of energy between organisms

organism types in a food chain

producers → consumers → apex predator → decomposers

what is a food web

lots of different possible food chains that are interconnected, better visualization of transfer of energy in an ecosystem

biomass pyramids

depict how the amount of biomass decreases as you go up trophic levels, as 10% of energy is transferred between each trophic level

how can biomass pyramids be innacurate

things like plankton that only have a small biomass at any time but reproduce quickly and therefore have a high rate of energy transfer: can be shown better with an energy pyramids that are usually always shaped like a true pyramid

how is energy lost in a food chain(5)

loss through maintaining body heat, respiration, movement, leftover pieces, indigestible parts excreted in waste.

is eating cows or grain more efficient

yes since cows are primary consumers and grain is a producer and since cows eat grain, 90% of energy from the grain cows consume is lost during the cow’s lifespan

how are invasive species bad

they can increase competition or kill and drive out the native species that used to live there

how are things transferred in an ecosystem

carbon oxygen hydrogen and nitrogen are all gotten from the soil passed down the food chain and then broken down back into the ground once the organisms die by decomposers

3 ways co2 is released into atmosphere

decomposition, respiration and burning of fossil fuels

why is nitrogen in the atmosphere useless

because it is unreactive so it can’t be used by animals unless turned into nitrate(no3) ions through nitrogen fixation

nitrogen fixation in lightning

there is so much energy in lightning that it causes the nitrogen and oxygen in the air react to form nitrates

why are nitrate ions important

they are needed to synthesize amino acids that are used in proteins that are essential for growth

deamination

when nitrogen from excess amino acids is broken down in the liver and turned into urea to be excreted

4 main microorganisms in the nitrogen cycle

decomposers, nitrifying bacteria, nitrogen-fixing bacteria, denitrifying bacteria

decomposers in nitrogen cycle

break down proteins in rotting plants and animals and urea in waste and turn them into ammonia which turn into ammonium(NH4+) in the soil when it dissolves

nitrifying bacteria in nitrogen cycle

ammonium ions from decomposers are turned into nitrate ions(NO2-) and then nitrates. process called nitrification, oxidizing ammonium ions or nitrate ions for energy

nitrogen fixing bacteria in the nitrogen cycle

in order to get nitrogen into a form that can be used nitrogen fixing bacteria break down the atmospheric N2 into ammonia and other nitrogen compounds that can be used

denitrifying bacteria in the nitrogen cycle

in order to produce energy the bacteria reduce nitrates and turn them back into N2 gas

4 factors that affect population growth

food supply(more birds when blackberries are in season), predation(more predators means less prey), disease(new pathogen that wipes out population), competition(invasive species increasing competition for food)

4 phases of sigmoid curve in population growth

lag phase(low numbers and low reproduction), exponential phase(plenty of resources and rapid reproduction), stationary phase(death and birth is in equilibrium due to carrying capacity reached due to limiting factors), death phase(no more materials to support population)