4a,b organisms in the environment and feeding relationships

Question 1

what are decomposers? give examples.

Answer 1

Saprobiotic organisms (such as bacteria or fungi) that break down dead organic tissue and releases carbon dioxide and simple compound and ions. (feed saprotrohically)

Question 2

what is saprotrophic nutrition?

Answer 2

The mode of nutrition in which organisms feed on dead and decaying matter.

Question 3

what is a producer?

Answer 3

plants which photosynthesise to produce food

Question 4

what are consumers?

Answer 4

animals that eat plants or other animals

Question 5

what are decomposers?

Answer 5

organisms that break down dead material and help to recycle nutrients

Question 6

what is the physical environment?

Answer 6

all the non-biological components of the ecosystem, e.g., water and soil in a pond or soil and air in a forest

Question 7

what are biotic/abiotic components of an environment?

Answer 7

the living and nonliving components of an organism

Question 8

what does an ecosystem contain?

Answer 8

a vareity of habitats

Question 9

what is population?

Answer 9

All the members of the same species within the same habitat.

Question 10

what does abiotic mean?

Answer 10

A physical or chemical factor affecting an ecosystem e.g. light intensity or temperature.

Question 11

what is community?

Answer 11

All of the living organisms within an ecosystem.

Question 12

what is habitat?

Answer 12

The particular place where a community of organisms is found.

Question 13

what is an ecosystem?

Answer 13

All of the living organisms in an area along with all the abiotic features of the environment.

Question 14

what is an environment?

Answer 14

The conditions surrounding an organism. Divided into abiotic features (e.g. temperature, water availability) and biotic factors (e.g. competition and predation).

Question 15

what does the term biodiversity mean?

Answer 15

The amount of variation shown by organisms in an ecosystem; it takes into account the number of different species and (relative) abundance (number) of each species.

Question 16

describe a practical where you could investigate the population size of an organism in 2 different areas

Answer 16

1. place the quadrats randomly on a numbered grid and note down the coordinates (like a 10x10m grid) or use a random number generator (on calculator) for the coordinates
2. go to the coordinates, place the quadrat down, and count the number of things e.g., dandelions
3. repeat this for 9 other quadrats in the same area
4. go to your second area and repeat the same process
   - create a table of results and then create a mean number of things per m^2 in each area.
5. does this support your hypothesis

Question 17

why is biodiversity good?

Answer 17

because an ecosystem dominated by 1 or 2 species is more likely to be affected by some sort of ecological disaster e.g., if a new disease arose that wiped out the dominant tee species, this would have an impact on other species that relied on the tree for food and shelter. in a more diverse ecosystem, other species might supply these resources

Question 18

describe a practical to compare the biodiversity of plants in 2 different habitats

Answer 18

maybe use random number generator to find the coordinates????
1. take 10 1m^2 quadrats to each area and sample the area
2. count the number of each plant species present in each quadrat
3. do the same in the other area
4. create a table with plant species and the total of each plant species in each area and 2 other columns
5. plot the result as 2 bar charts and the same axis scales for each bar chart. then compare and describe the biodiversity in the two areas.

Question 19

give some examples of interaction in ecosystems

Answer 19

feeding among organisms (constant recycling of the same nutrients through the ecosystem).
competition among the organisms (animals compete for shelter, food, mates, plants for co2, mineral ions, light, water).
interactions between organisms and the environment (plants absorb mineral ions, CO2, water from the environment. plants give off water vapor, oxygen, animals use materials from environment to build shelter. temp can affect processes in organisms and vice versa)

Question 20

what are some biotic factors? name them.

Answer 20

availability of food and competition for food resources predation
parasitism
disease
presence of pollinating insects
availability of nest sites.

Question 21

what are some abiotic factors? name them.

Answer 21

climate, such as light intensity, temperature and water availability
hours of daylight
soil conditions, such as clay content, nitrate level, particle size, water content and pH

other factors specific to a particular habitat, such as salinity (salt content) in an estuary, flow rate in a river, or oxygen concentration in a lake
pollution.

Question 22

what are the main abiotic factors of a river?

Answer 22

depth of water flow rate
type of material at the bottom of the stream (stones, sand, mud etc.)
concentration of minerals in the water
pH
oxygen concentration
cloudiness of the water
presence of any pollution.

Question 23

biotic factors affecting animals in a river?

Answer 23

food supply, either from plants or other animals. large fish could not live in a shallow stream.

Question 24

what is a producer?

Answer 24

Organisms which produce complex molecules from simple ones using an additional energy source, e.g. plants producing glucose in photosynthesis.

Question 25

what is a primary consumer?

Answer 25

An organism which feeds on plants.

Question 26

what is a secondary consumer?

Answer 26

Animals that eat herbivores.

Question 27

what is a tertiary consumer?

Answer 27

A tertiary consumer is an animal that eats primary and secondary consumers in a food chain, and is usually at the top of the food chain. e.g. lions

Question 28

what is a trophic level?

Answer 28

One of the steps in a food chain.

Question 29

what is the fifth link in a trophic level called?

Answer 29

quantertiary consumer

Question 30

what is another way of describing a food chain?

Answer 30

it shows how energy is moved from one organism to another as a result of feeding

Question 31

why are food chains useful?

Answer 31

they are a convinient way of showing the feeding relationships between a few organisms in an ecosystem. they can also let you predict what woudl happen if the numbers of one organism in a food chain dropped easily. HOWEVER they oversimplify the situation. therefore, a food web may be more useful as it shows that interrelationships exist within and between foodchains in an ecosystem

Question 32

what are the two types of ecological pyramids?

Answer 32

pyramids of numbers, pyramids of biomass

Question 33

what is a pyramid of biomass?

Answer 33

A way of describing the relationship between different trophic levels in an ecosystem. Refers to the amount of biomass in each trophic level at a specific time. (twhaotal mass of organism in each trophic level)

Question 34

what is a pyramid of numbers?

Answer 34

A way of describing the relationship between different trophic levels in an ecosystem. Refers to the number of organisms (irrespective of mass) in each trophic level at a specific time.

Question 35

what is a pyramid of energy?

Answer 35

A way of describing the relationship between different trophic levels in an ecosystem. Refers to the amount of energy in each trophic level over a period of time.

Question 36

in a pyramid of ecology (idk) what is on the bottom/top?

Answer 36

bottom-producer
top-secondary/tertiary consumer (whatever is last)

Question 37

what is biomass?

Answer 37

The measure of mass of living material present of a species, measured in g per meter squared. (or total mass of a plant/animal with total water removed for dry biomass which is more reliable because water content of organisms varies with environmental conditions)

Question 38

why are diagrams of feeding relationships a pyramid shape?

Answer 38

because..
some parts of the grass are not eaten (the roots for example)
some parts are not digested and so are not absorbed - even though rabbits have a very efficient digestive system
some of the materials absorbed form excretory products
many of the materials are respired to release energy, with the loss of carbon dioxide and water.

Question 39

what is Biomagnification?

Answer 39

The increase in concentration of bioaccumulated substances (e.g. pollutants) along a food chain.

Question 40

what is bioaccumilation?

Answer 40

Build up of pollutants in an organism.

Question 41

what is BOD?

Answer 41

Biological Oxygen Demand; the amount of oxygen in water used up by organisms, measured in mg per litre.

Question 42

what is a carnivore?

Answer 42

An organism which feeds on other organisms.

Question 43

what is a consumer?

Answer 43

Organism that eats other organisms.

Question 44

what is interspecific competition?

Answer 44

Competition between organisms of different species.

Question 45

what is intraspecific competition?

Answer 45

Competition between organisms of the same species.

Question 46

what is an omnivore?

Answer 46

An animal which eats both plant and animal matter.

Question 47

what is a predator? what is prey?

Answer 47

predator - An organism that feeds on another organism, killing it before eating it.
prey - An organism hunted and killed for food.

Question 48

what is a quadrat?

Answer 48

Quadrat

Question 49

what is a species?

Answer 49

A group of similar organisms that are able to breed together to produce fertile offspring.

Question 50

what does an energy flow diagram show?

Answer 50

the main ways energy is transferred within an ecosystem and between the trophic levels of the ecosystem

Question 51

why is only 10% of energy tansferred from one trophic level to the next?

Answer 51

some parts of the grass are not eaten (the roots for example)
some parts are not digested and so are not absorbed - even though rabbits have a very efficient digestive system
some of the materials absorbed form excretory products
many of the materials are respired to release energy, with the loss of carbon dioxide and water.

Question 52

what are the key ideas involved in the flow of energy (diagrams though ecosystems)?

Answer 52

• Photosynthesis ‘fixes’ sunlight energy into chemicals such as glucose and starch.
• Respiration releases energy from organic compounds such as glucose.
Almost all other biological processes (e.g. muscle contraction, growth, reproduction, excretion, active transport) use the energy released in respiration.
If the energy released in respiration is used to produce new cells, then the energy remains ‘fixed’ in molecules in that organism. It can be passed on to the next trophic level through feeding.
If the energy released in respiration is used for other processes then it will, once used, eventually escape as heat from the organism. Energy is therefore lost from food chains and webs at each trophic level.

Question 53

what does a flow of energy diagram look like?

Answer 53

look at pg. 197

Question 54

if only 10% of energy is transfered at each tropich level, of the original 100% of the energy, how much gets tot he secondary consumer?

Answer 54

100% - 10% - 1%-0.1%
(divide by 10 each time)
a secondary consumer gets 1% of initial energy