2.2

Question 1

systems

Answer 1

have inputs and outputs processes

Question 2

respiration

Answer 2

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.

Question 3

aerobic respiration equation

Answer 3

Glucose + oxygen —-> carbon dioxide + water + energy

Question 4

second law of thermodynamics entropy (disorganisation)

Answer 4

Heat dissipates throughout the ecosystem,
making it more disorganized (never 100%
efficient)

Question 5

how glucose acts as energy storage

Answer 5

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

Question 6

photosynthesis word equation

Answer 6

carbon dioxide + water ———> glucose + oxygen

Question 7

how trees benefit from photosynthesis

Answer 7

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.

Question 8

trophic level

Answer 8

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

Question 9

why T4 is usually the highest trophic level in terresterial ecosystem ?

Answer 9

due to significant
losses of energy between trophic
levels.

Question 10

explain chemosynthetic (bacteria)

Answer 10

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

Question 11

producer function

Answer 11

1. Provide energy for other trophic levels
2. Habitat for other organisms

Question 12

primary consumer function

Answer 12

Disperse seeds

Question 13

secondary and tertiary consumer function

Answer 13

Pollinate flowers

Question 14

decomposer and detritivore function

Answer 14

Breaking down dead organisms

Releasing nutrients to cycle(nitrogen)

Question 15

autotrophs

Answer 15

Organisms which can
synthesise their own
organic molecules from
simple inorganic
molecules (CO2 and H2O)

Question 16

Heterotrophs

Answer 16

Organisms who must
obtain organic
compounds from the
bodies of other organisms

Question 17

food chain

Answer 17

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.

Question 18

food web

Answer 18

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

Question 19

detritivores

Answer 19

heterotrophs that obtain nutrients from detritus (dead particulate organic material) by** internal organ**

exp: earthworms

Question 20

saprotrophs

Answer 20

Heterotrophs that obtain nutrients from
dead organisms by external digestion

1.saprotrophs secrete digestive enzyme onto dead organisms
2.absorbs digested material

exp: fungi

Question 21

ecological pyramids

Answer 21

quantitative model

there are three types:
1. pyramid of biomass
2. pyramid of productivity/energy
3. pyramid of numbers

Question 22

pyramid of numbers

Answer 22

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

Question 23

pyramid of biomass

Answer 23

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

Question 24

pyramid of productivity

Answer 24

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%.

Question 25

strengths and weaknesses of pyramid of productivity

Answer 25

strengths:
Most accurate as they show actual
energy available
Ecosystems can be compared

weaknesses:
Data collection is not easy

Question 26

how energy are lost between trophic levels?

Answer 26

material not consumed
material not assimilated (fecal waste)
cell respiration

Question 27

biomagnification

Answer 27

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

Question 28

bioaccumulation

Answer 28

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

Question 29

differences between bioaccumulation and biomagnification

Answer 29

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

Question 30

similarities between bioaccumulation and biomagnification

Answer 30

• bioaccumulation can lead to biomagnification
• toxins are ingested
• concentration gets higher over time