organisms and their environment

Question 1

ecology

Answer 1

the study of organisms in their environment

Question 2

habitat

Answer 2

the place where an organism lives
each species has adaptive feature that enables it to live in its specific habitat

Question 3

community

Answer 3

all of the populations of all the different species in an ecosystem

Question 4

ecosystem

Answer 4

a unit containing all of the organisms in a community and their environment, interacting together

Question 5

niche

Answer 5

the role of an organism in its natural environment; the way in which it interacts with other organisms and with the non-living parts of the environment

Question 6

all living organisms need

Answer 6

energy
all the energy in an ecosystem originates from the sun

Question 7

what happens to the energy from the sun

Answer 7

captured by plants and used to make organic nutrients- glucose, starch, and other organic substances such as fats and proteins.

Question 8

how do animals get their energy

Answer 8

by ingesting plants or by eating animals which have eaten plants

Question 9

food chain

Answer 9

a diagram showing the flow of energy from one organism to the next, beginning with a producer.

Question 10

food web

Answer 10

a network of interconnected food chains

Question 11

producer

Answer 11

an organism that makes its own organic nutrients, generally using energy from sunlight, through photosynthesis.
they produce the energy-containing organic nutrients that all the other organisms in the food chain need.

Question 12

consumers

Answer 12

an organism that gets its energy by feeding on other organisms

Question 13

primary consumer

Answer 13

an animals that gets it energy from eating plants

Question 14

secondary consumer

Answer 14

an animal that eats the primary consumer

Question 15

tertiary consumer

Answer 15

an animal that eats the tertiary consumer

Question 16

herbivores

Answer 16

an animal that gets it energy from eating plants

Question 17

carnivores

Answer 17

an animal that gets energy from eating other animals

Question 18

decomposer

Answer 18

an organism that gets its energy from dead or waste organic material.

Question 19

what happens to the energy across trophic levels (along the food chain)

Answer 19

some energy is passed on to the next level. most is lost

Question 20

how is energy lost along the food chain

Answer 20

when an organisms used glucose for respiration, some of the energy released from the glucose is lost as heat energy.
weh none organism eats another it rarely eats all of it. so not all if the energy is transferred
when an organism eats another the enzymes break down the molecules so that they can be absorbed, but sometimes they arent and they pass through the alimentary canal and are lost as faeces.

Question 21

further along the food chain…

Answer 21

less energy available for each trophic level.
near the beginning of the food chain is the best way to eat without

Question 22

pyramid of numbers

Answer 22

a diagram in which the area of the bar at each trophic level shows the relative number of organisms at that level in the food chain
usually the shape is big to small (producer is big pop.) because there is less energy available as you go up so less animals

Question 23

trophic level

Answer 23

the position of an organism in a food chain, food web or pyramid of biomass or numbers

Question 24

pyramid of biomass

Answer 24

a graph showing the relative quantity of biomass at each trophic level.
better than pyramid of numbers bc it gives a better representaiton of the quantity of energy at each level

Question 25

pyramid of energy

Answer 25

a graph showing the relative quantity of energy at each trophic level kJ/m2

Question 26

how to measure energy in animals

Answer 26

killing, then burning it to measure how much energy how much energy is released best way to measure energy

Question 27

why are decomposer important

Answer 27

they help to release substances from dead organisms, the released substances can then be used by other living organisms. 2 or the substances are carbon and nitrogen

Question 28

nitrogen fixation

Answer 28

converting inert nitrogen gas into a more reactive form, such as nitrate ions or ammonia there are several ways to do this: lighting artificial fertilisers nitrogen fixing bacteria

Question 29

lightning

Answer 29

makes some of the nitrogen gas in the air cobined with oxygen, forming nitrogen oxides. they dissolve in rain and are washed into the soil, where they form nitrates

Question 30

artificial fertilisers

Answer 30

nitrogen and hydrogen can be made to react in an industrial chemical process to make ammonia. they ammonia is used to make ammonium coumpounds and nitrates, sold as fertilisers

Question 31

nitrification

Answer 31

converting ammonium ions to nitrate ions

Question 32

denitrification

Answer 32

converting nitrate ions to nitrogen gas

Question 33

what happens to a population's size

Answer 33

stays roughly the same

Question 34

lag phase

Answer 34

the stage at the start of a population growth curve where the population remains small and grows only very slowly

Question 35

log or exponential phase

Answer 35

the stage in a population growth curve where the population grows at its maximun rate; birth rate exceeds death rate

Question 36

stationary phase

Answer 36

the stage in a population growth curve where the population falls; death rate exceeds birth rate .

Question 37

sigmoid growth curve

Answer 37

an S-shaped curve showing change in the size of a population through all the phases in population growth

Question 38

limiting factors in population size

Answer 38

food supply disease no. of predators

Question 39

limiting factor

Answer 39

a factor that is in short supply, which stops an activity happening at a faster rate

Question 40

age pyramid

Answer 40

a diagram showing the relative numbers of individuals of different stages in a population

Question 41

the human population is...

Answer 41

stably increasing

Question 42

nitrogen cycle steps

Answer 42

- plants use fixed nitrogen to make amino acids and then proteins - animals eat the plants, therefore gettin thier N in the form of protein - when a animal or plant dies, decomposers break down proteins into ammonium ions and this is released - a group of bacteria called nitryfing bacteria turn the ions into nitrates, which plants can use again (nitrification) - another group of bacteria, denitrifying bacteria, complete the nitrogen cycle. do a process called denitrification- converting nitrate ions into nitrogen gas the gas goes back into the atmosphere.

Question 43

carbon cycle steps

Answer 43

- 0.04% of air in carbon - during photosynthesis, C atoms from CO2 become part of glucose and starch molecules in the plant - some glucose is used in respiration by the plants and becomes part of CO2 again in air - some of the carbon- containing molecules in the plant will be eaten by animals - animals respire, releasing C back into the air as COn - decomposers feed on waste materials like urine snd faeces - decomposers repsire, released some C back into the air as CO2 - some waste products and dead bodies that are not decomposed get buried in sediments. over a long period of time -> turn into fossil fuels.