Biology C4.2

define ecosystem

all the organisms and abiotic factors, eg water rock sunlight etc, in an area

whats the difference between open and closed systems

Open system:

resources (matter and energy) can enter and exit

Closed system:

energy can enter and exit, but not matter

define autotrophs and tell me the two main types of autotrophs

• Autotrophs synthesize organic compounds from inorganic molecules using sunlight or inorganic compounds as energy sources.

→ photoautotrophs use sunlight

→ chemoautotrophs use chemical reactions (cave ecosystem, deep ocean)

what is something that rely on consuming other organisms or organic matter to obtain energy and nutrients for survival.

heterotrophs 

define anabolic and catabolic reaction and describe what it does to energy when it occurs

anabolic reactions: building larger molecules with smaller molecules, energy stored

catabolic reaction: breaking down larger molecules into smaller molecules, energy release

what limits the length to food chains

Only 10-20% of energy moves from one level to the next, because:

• movement (catching/ eroding predators) Loss of energy in the form of heat

• Heat loss -

  a consequence of energy conversion during cell respiration.

• metabolism (meaning all the chemical reaction the body does) eg. Respiration

• undigested waste - eg. barn owl would be bones, teeth, hair, etc

this energy loss restricts length of food chains

what is the unit for pyramids of biomass and pyramids of energy 

energy= calories/kilocalories or joules/ kilojoules 

tell me what a decomposer does and the two types of decomposers

Decomposers

break down dead organisms and organic matter, releasing essential nutrients back into the environment.

→ they exist at all trophic levels

Saprotrophs: Does external digestion (Fungi, bacteria), through secreted digestive enzymes into their environment

Detritivores: Feed on detritus (dead stuff) and do internal digestion (vulture, dung beetle)

define flux, sinks and sources, and give me 2 examples each

Flux: movement from one place to another,

includes: photosynthesis, respiration, decomposition, combustion and carbon sequestration

Sink: an organism in an ecosystem that absorbs more carbon than it releases , not necessary long term, trees, ocean, soil, rocks, peat

Sources: releasing carbon from a sink/ reservoir

• Burning fossil fuels

• Respiration

• Livestock + methane gas production

define anaerobic and methanogens

anaerobic: organisms that do not use oxygen to respire

eg anaerobic bacteria (methanogens) uses hydrogen uses hydrogen to break down organic molecules

Methanogens: bacteria that produces methane in anaerobic respiration

what is this called, tell me why is there an steadily increase and the fluxes in the increases

keeling curve’s steady increase shows the increase of CO2 throughout the years

the equal rise and fall shows, rising in the winter when leaves drop and CO2 storage in plants has decreased

drop in CO2 is during the summer when plants bloom and plants undergo more photosynthesis