2.2 Flashcards
systems
have inputs and outputs processes
respiration
oxidation of glucose to
release energy that is then** used in all
activities **in the organism.
The energy is “stored” within the chemical
bonds of the glucose, and as the glucose is
broken down the energy released is used to
create another chemical, ATP, which our
cells can readily use.
aerobic respiration equation
Glucose + oxygen —-> carbon dioxide + water + energy
second law of thermodynamics entropy (disorganisation)
Heat dissipates throughout the ecosystem,
making it more disorganized (never 100%
efficient)
how glucose acts as energy storage
plants undergo photosynthesis and produce glucose
glucose has chemical energy
glucose is made up of carbon, hydrogen, and oxygen
the chemical bond between the elements hold energy
once it is broken, energy is released
photosynthesis word equation
carbon dioxide + water ———> glucose + oxygen
how trees benefit from photosynthesis
glucose is stored asa plant tissue thus forming the basis of plant biomass
trees use carbon dioxide and undergo photosynthesis to isolate carbon and use it to produce tree bark, leaves, tree trunks, etc.
trophic level
the position an
organism (or group of organisms in a
community) occupies in the food chain
can be classified into
producer
autotrophs
chemosynthetic (produce food without sunlight)
consumer
heterotrophs
why T4 is usually the highest trophic level in terresterial ecosystem ?
due to significant
losses of energy between trophic
levels.
explain chemosynthetic (bacteria)
hot water in hydrothermal vent is saturated with dissolved chemicals
bacteria absorbs hydrogen sulfide and carbon dioxide from the vent water and oxygen from the seawater
bacteria uses energy released by oxidising of sulfur to form organic molecules
producer function
- Provide energy for other trophic levels
- Habitat for other organisms
primary consumer function
Disperse seeds
secondary and tertiary consumer function
Pollinate flowers
decomposer and detritivore function
Breaking down dead organisms
Releasing nutrients to cycle(nitrogen)
autotrophs
Organisms which can
synthesise their own
organic molecules from
simple inorganic
molecules (CO2 and H2O)
Heterotrophs
Organisms who must
obtain organic
compounds from the
bodies of other organisms
food chain
A food chain is a linear sequence of organisms through which nutrients and energy
pass as one organism eats another
Each food chain should include a
producer and consumers, but not
decomposers.
food web
The food web shows all of the relationships between all of the plants and animals in
a community.
Show all the possible FOOD CHAINS.
Show all the OMNIVORES.
Show MULTIPLE feeding preferences.
lukis producer kat bawah, naik ke atas (consumer)
decomposer lukis bawah producer
detritivores
heterotrophs that obtain nutrients from detritus (dead particulate organic material) by** internal organ**
exp: earthworms
saprotrophs
Heterotrophs that obtain nutrients from
dead organisms by external digestion
1.saprotrophs secrete digestive enzyme onto dead organisms
2.absorbs digested material
exp: fungi
ecological pyramids
quantitative model
there are three types:
1. pyramid of biomass
2. pyramid of productivity/energy
3. pyramid of numbers
pyramid of numbers
May not be pyramid-shaped because all
organisms are counted as equal regardless of
size (when
individuals at lower trophic levels are relatively large)
1 pokok untuk 1000 caterpillars
different biome has different pattern of pyramid of numbers exp grassland and temperate forest have different pyramid shape during summer
strength
Non-destructive method of data
collection
Useful in comparing changes in a
number of individuals over time
weakness
Some animals feed at more than
one trophic level (omnivore)
Numbers can be too great to
represent accurately
pyramid of biomass
A graphical representation of
the amount of biomass at each
trophic level
Calculate dry mass and energy
content
Biomass contains energy;
therefore, less energy at a
trophic level means less
biomass
Represents standing stock
(fixed point in time)
unit is either kg/m2 or J/m2
aquatic ecosystems can have inverted pyramid when growth is rapid and seasonal
however if average biomass over a year is calculated, the shape is normal
strength
Overcome the problems of counting
seen in PN
weakness
Destructive and unethical
Seasonal variation
pyramid of productivity
Shows the turnover of biomass at each trophic level.
unit kg/ha/yr or J/ha/yr
rate of which energy or mass is transferred from one trophic level to the next
Pyramids of productivity for entire ecosystems over a year always show a decrease along
the food chain.
the pyramid of productivity in a healthyecosystem is always pyramid shaped. This is due to the 10% rule and the energy efficiency (2nd law of thermodynamic)
the process of energy transformation is never 100% efficient, commonly being 10–20%.
strengths and weaknesses of pyramid of productivity
strengths:
Most accurate as they show actual
energy available
Ecosystems can be compared
weaknesses:
Data collection is not easy
how energy are lost between trophic levels?
material not consumed
material not assimilated (fecal waste)
cell respiration
biomagnification
increase in the concentration of the pollutant
as it moves up through the food chain.
exp: toxin is poisonous (DDT and mercury)
These substances accumulate in the food chain and damage the organisms in it,** particularly in the predators** at the end of the chain.
main toxins in the environment are** heavy metals** and** organic pollutants**
top carnivore is the most harmed in the food chain
bioaccumulation
increase in the concentration of a pollutant in
an organism as it absorbs or it ingests it from its environment
Each consumer, therefore, absorbs the accumulated pollutant from each individual organism it eats
differences between bioaccumulation and biomagnification
bioaccumulation:
accumulutaion within an organism
toxins ingested are at high rate than being eliminated
biomagnification:
the higher the thropic level, the greater the risk
increase concentration of toxins as it moves up from one trophic level to another
similarities between bioaccumulation and biomagnification
- bioaccumulation can lead to biomagnification
- toxins are ingested
- concentration gets higher over time
