environmantal interactions

Question 1

what is a habitat

Answer 1

the place where an organism lives

Question 2

what is a population

Answer 2

all the organisms of 1 species in a habitat

Question 3

what is a community

Answer 3

all the different species in a habitat

Question 4

what’s in an eco system?

Answer 4

all organisms living in a particular area + all the abiotic conditions.

Question 5

investigate the population size of an organism in 2 different areas using a quadrat

Answer 5

• place a 1m2 quadrant on the ground in a random place in the 1st area (use a random number generator and make area a grid)
• count all of the organisms within the area of the quadrat.
• repeat this 10 times in the area using different places each time
• find the mean number of organisms per quadrat from the first sample area
• repeat all of this in the 2nd sample area
• compare the 2 sample area means

Question 6

what are 2 abiotic factors affecting the population size and distribution of organisms

Answer 6

environmental conditions- temperature levels, light intensity, moisture level, soil pH and wind speed

toxic chemicals - chemical pesticides or fertilisers.

Question 7

what are 3 biotic factors affecting the population size and distribution of organisms

Answer 7

availability of food
number of predators
competition ( for light, space, water, food and minerals from soil)

Question 8

what is a trophic level?

Answer 8

the stage of a food chain such as a producer, primary consumer, secondary consumer and tertiary consumer.

Question 9

what is a pyramid of numbers?

Answer 9

each bar of the pyramid shows the number organisms per trophic level, starting with the producer at the bottom (as it has the most organisms)
irregular pyramid shape

Question 10

what is the pyramid of biomass?

Answer 10

each bar of the pyramid shows the mass of the living material per trophic level, typically a pretty regular pyramid

Question 11

what is a pyramid of energy transfer?

Answer 11

shows the energy transferred to each trophic level in a food chain. so how much energy is passed from one level to the next.
always a regular pyramid shape.

Question 12

how much of the total energy available becomes biomass?

Answer 12

10%

Question 13

90% of energy is lost in different ways when going from 1 trophic level to the next, what are the ways this 90% is lost?

Answer 13

• roots and bones that aren’t eaten by the organism
• parts such as fibre are indigestible so pass through as waste
• respiration
• heat loss

Question 14

what is photosynthesis in the carbon cycle

Answer 14

it powers the whole system, plants use the CO2 from the air

Question 15

what is respiration in the carbon cycle

Answer 15

animals and plants release CO2 into the air

Question 16

what is combustion in the carbon cycle

Answer 16

animals and plants produce products - eg clothes, wood. which are burnt, putting CO2 into the air

Question 17

what is decomposition in the carbon cycle

Answer 17

bacteria and fungi break down waste and dead matter, releasing CO2 into the air - by respiration.

Question 18

name the greenhouse gases

Answer 18

water vapour 
carbon dioxide
methane
CFCs
nitrous oxide

Question 19

name 3 human activites that produce CO2

Answer 19

• car exhausts
• industrial processes
• deforestation

Question 20

2 human activities producing methane

Answer 20

• rice growing

- cattle rearing

Question 21

human causes that produce CFCs

Answer 21

-in aerosols and fridges, CFCs damage the ozone layer

Question 22

what is the greenhouse effect?

Answer 22

the greenhouse gases trap energy from the sun and re-radiates heat in all directions, including to earth. without the gases there would be nothing to keep the energy in and temperature would decrease rapidly

Question 23

what is global warming and why is it happening?

Answer 23

as humans increase the level of CO2, we also increase levels of other greenhouse gases. this has enhanced the greenhouse effect resulting in rising earth temperature

Question 24

what are the consequences of global warming

Answer 24

global warming is a type of climate change. it leads to extreme weather such as: rising sea levels, droughts and flooding due to ice burgs melting because of rising temperature. this causes habitat loss and effects food webs and crop growth.