Ecosystems and environment

Question 1

what is an ecosystem

Answer 1

An ecosystem is made up of a community interacting with the abiotic elements of their environment

Question 2

what do ecosystems have (3)

Answer 2

producers,consumers and decomposers

Question 3

what are producers

Answer 3

Ecosystems always have the following:
Producers = plants - produce their own food using photosynthesis

Question 4

whata are consumers

Answer 4

Consumers = organisms that eat other living organisms (this could be plants or animals)

Question 5

what are decomposers

Answer 5

Decomposers = organisms that break down dead organisms and help recycle their materials –> commonly bacteria and fungi

Question 6

what are biotic components

Answer 6

Biotic components = components to do with living organisms

Question 7

what are abiotic components

Answer 7

Abiotic components = physical things in the environment

Question 8

what are biotic componets

Answer 8

Biotic Factors: components to do with living things

Question 9

what is a habitat

Answer 9

Habitat = place where an organism lives
Population = at one point of time, in one place, all the individuals of a particular species

Question 10

what are abiotic factors (6)

Answer 10

Abiotic factors:
Light Intensity
Temperature
Moisture levels
Soil pH and mineral levels
Wind intensity and direction
Availability of O2

Question 11

what are biotic factors (5)

Answer 11

Biotic Factors:
Availability of food
New pathogen + parasites
New predators arriving
Interspecific competition (competition between species)

Question 12

how does availability of food affect the environment

Answer 12

availability of food - animals may move to a new food source, or die of starvation if there is less food

Question 13

how does new pathogens/parasites affect the environment

Answer 13

new pathogens can wipe out species. However, species can develop mutations which make them immune to the pathogen/parasites, parasites and pathogens can do the same also

Question 14

how does new predators affect the environment

Answer 14

new predators can disrupt the food chain and if there are too many predators, a species can die out. Alternatively, organisms with no defence against the new predator can die out. As a consequence, the predators acn die since there is nothing to eat.

Question 15

how does competition between species affect the environment

Answer 15

competition between species - A new species may outcompete another to the point where numbers are too low for breeding

Question 16

how does light intensity effect the environment

Answer 16

Light Intensity - light limits photosynthesis so it will affect the distribution of plants and animals

Question 17

how does light intensity effect the environment

Answer 17

Temperature - limits photosynthesis –> affects plants, so affect herbivores, so it affects carnivores

Question 18

how does moisture levels effect the environment

Answer 18

Moisture levels - no water means little or no life

Question 19

how does soil ph and mineral levels effect the environment

Answer 19

Soil pH and mineral levels - plants can die leading to herbivores dying. In low mineral soil, carnivorous plants can survive due to animal protein

Question 20

how does wind intensity and direction effect the environment

Answer 20

Wind intensity and direction - plants may wilt due to the wind intesnity, maintaining a steep concentration gradient for diffusion of water vapour, so plants have a high rate of transpiration. affects the shape of trees and the whole landscape

Question 21

how does availability of 02 effect the environment

Answer 21

Availability of O2 - plants and animals may die. O2 levels in the air don’t vary as much, so this is a bigger concern for water-living organisms.

Question 22

what is quadrat

Answer 22

A quadrat is a square frame that is laid on the ground

Question 23

why must you make sure when deciding a quadrat size

Answer 23

Although there are different sized quadrats, you must keep the size you use consistent for the species you measure.

Question 24

why are quadrats used

Answer 24

Quadrats are used to investigate the size of the population of plants, and animals that move very slowly, like snails

Question 25

to ensure quadrats results are reliable, what must be done (3)

Answer 25

To ensure that the results are reliable, random sampling is used
Random sampling: choosing the area in which to place the quadrat
Choose your sample area, and make coordinates in this sample grid
Use a random number generator/ a random coordinate generator to choose where to place the quadrat

Question 26

why are other methods of results being reliable wrong in other exam boards (2)

Answer 26

Other boards also mention a method of spinning in a circle with eyes closed and throwing the quadrat however this is WRONG - never mention this as a correct method
Problems with this method:
It is not a random method, as before throwing, you choose where to stand to throw it
2. How far it is thrown, is dependent person to person

Question 27

what is quantative sampling

Answer 27

Quantitative sampling = finding the mean number of organisms per m^2

Question 28

how do plants interact for the enviornment

Answer 28

Feeding cycle: the plants, animals and decomposers recycle the same nutrients
Interactions between organisms and the environment:
Plants TO the environment: plants release oxygen to help the animals respire in th environment. They also release water vapour

Question 29

how does the environment help the plants

Answer 29

Plants FROM the environment:plants feed of the minerals from the ground, and photosynthesise from the sun. Plants also absorb CO2 and water

Question 30

what do animals do for the environment

Answer 30

Animals TO the environment: release feaces to fertilise the soil and die also to fertilise the soil and feed other animals. Some heat which MAY affect the temperature

Question 31

what do animals do for the environment

Answer 31

Animals FROM the environment: use materials from the environment to build shelters, and respire - take in oxygen

Question 32

what do animals compete for

Answer 32

Animals compete for:
1. Food
2. Territory
Nesting sites
3. Mates

Question 33

what do plants compete for

Answer 33

Plants compete for:
Space to grow - allowing roots to absorb water, and leaves to catch light
Light for photosynthesis
Water for photosynthesis and to keep their tissues turgid and supported
Nutrients (Minerals) from the soil to make necessary chemicals in cells
To attract insects for insect-pollination, or access to wind for wind-pollination

Question 34

abiotic factors for antarcic (6)

Answer 34

temperature
water availability
temperature of water
rough terrain
avalanches
duration of sunlight

Question 35

abiotic factors for river (10)

Answer 35

temperature of water
current- Flow rate
terrain of river path
nature of the river bed, hard rock, big rocks, sediment etc
water pollution
salt/freshwater
pH
concentration of minerals/nutrients
concentration of oxygen in the water
Depth of river
Cloudiness of water

Question 36

what are the levels in a foodchain called

Answer 36

These levels in the food chain (producer, primary/secondary consumer etc) are called Trophic Levels

Question 37

what are the trophic levels called in a food chain

Answer 37

A–>B–>C–>D–>E
–> = eaten by
A=Producer
B= Primary Consumer = Herbivores
C= Secondary Consumer = Carnivores
D=Tertiary Consumer
E=Quaternary Consumer
E, at the end of the food chain is called a Top Carnivore