human influences on the environment

Question 1

what does making food production more intensive mean

Answer 1

producing food more efficiently with a finite amount of land and resources

Question 2

what is an agricultural machinery and what has it done

Answer 2

tractors, combine harvesters
increased food supply
can harvest much larger fields

Question 3

what are chemical fertilisers and what have they done

Answer 3

fertilisers increase the amount of nutrients in the soil for plants, meaning that they can grow larger and produce more fruit
increased food supply

Question 4

what are insecticides and herbicides

Answer 4

are chemicals that kill off unwanted insects and weed species, meaning that there is less damage done to plants and fruit lost to insects (insecticides), as well as reducing competition from other plant species (herbicides)

Question 5

what is selective breeding

Answer 5

animals and crop plants which produce a large yield are selectively bred to produce breeds that reliably produce high yields

Question 6

what is monoculture farming?

Answer 6

means that on a given area of agricultural land only one type of crop is grown

Question 7

the disadvantages of monoculture

Answer 7

there is very low biodiversity
increase in pest population
reduction in soil fertility

Question 8

the disadvantages of insecticides

Answer 8

harmless insects being killed
pollution by pesticides (persistent chemicals which accumulate in food chains)
pests can become resistant to insecticides

Question 9

biodiversity definition

Answer 9

number of different species that live in a particular area

Question 10

what is a major cause of a reduction in biodiversity

Answer 10

habitat destruction

Question 11

main reasons for habitat destruction

Answer 11

clearing land for farming and houses
extraction of natural resources
marine pollution

Question 12

what are the downsides of deforestation

Answer 12

extinction/loss of biodiversity
soil erosion
flooding
increased carbon dioxide in atmosphere

Question 13

consequence of soil erosion

Answer 13

without trees nutrients and minerals will remain in the soil and will wash away into water bodies by the rain
the loss of soil nutrients are permanent and makes it very hard for forrest trees to regrow

Question 14

consequence of flooding

Answer 14

without trees the topsoil will be loose and can be easily washed away by the water, increasing the chance of flash floods and landslides

Question 15

consequence of increased co2 in the atmosphere

Answer 15

contributing factor to global warming

Question 16

what can untreated sewage cause in water

Answer 16

provides a good breeding ground for bacteria which increase rapidly depleting the oxygen dissolved in the water causing the death of fish
eutrophication

Question 17

what can chemical waste cause in water

Answer 17

do not breakdown and can build up in foodchains poisoning the top carnivores

Question 18

what can discarded rubbish cause in water

Answer 18

animals can eat the waste hindering the food chain

Question 19

what can fertilizers cause in water

Answer 19

more algae which will consume the dissolved oxygen again leading to eutrophication

Question 20

what can insecticides and herbicides cause in water

Answer 20

loss of biodiversity, can build up toxic concentrations and harm other animals

Question 21

how does algal bloom affect aquatic plants

Answer 21

blocks the sunlight, preventing it from reaching the plants and hence they die

Question 22

what are the negative effects of plastic pollution on land

Answer 22

As it breaks down, it releases toxins into the surrounding soil and as such the land is no good for growing crops or grazing animals.

Question 23

how is acid rain formed

Answer 23

Combustion of fossil fuels that contain sulfur impurities creates sulfur dioxide
mixes with oxygen in air to form sulfur trioxide
sulfur trioxide dissolves in water droplets in clouds to form acid rain

Question 24

what are the effects of acid rain

Answer 24

damage to leaves, killing plants
acidification of leaves, killing animals
increased risk of asthma attacks and bronchitis in humans
lowers ph of lakes when dissolved in them and kills fish

Question 25

process of eutrophication of water

Answer 25

- increased availability of nitrate and other ions * increased growth of producers * increased decomposition after death of producers * increased aerobic respiration by decomposers * reduction in dissolved oxygen * death of organisms requiring dissolved oxygen in water

Question 26

what is a sustainable resource

Answer 26

one which is produced as rapidly as it is removed from the environment so that it does not run out

Question 27

which resources can be conserved and maintained sustainably

Answer 27

forests and fish stocks

Question 28

how does methane and carbon dioxide emission pollute our atmosphere

Answer 28

methane and carbon dioxide act as a blanket around the atmosphere and trap gasses insulating the earth causes global warming and climate change polar/ice caps are melting

Question 29

what is sustainable development defined as

Answer 29

development providing for the needs of an increasing human population without harming the environment

Question 30

why have some organisms become endangered or have gone extinct

Answer 30

climate change, habitat destruction, hunting, overharvesting, pollution and introduced species

Question 31

how can endangered species be conserved

Answer 31

monitoring and protecting species and habitats education captive breeding programmes seed banks

Question 32

what are seed banks

Answer 32

seeds of endangered plant species are carefully stored so that new plants may be grown in the future

Question 33

when can a species be at risk of extinction

Answer 33

if there is not enough genetic variation in the population as random changes in the environment may quickly cause extinction because the remaining organisms are all very similar and may not have the adaptations to survive such changes

Question 34

why are conservation programs important

Answer 34

maintaining or increasing biodiversity reducing extinction maintaining ecosystem functions

Question 35

what are the uses of Artificial Insemination and IVF

Answer 35

Both help maintain biodiversity IVF: This allows gametes with known alleles to be used in ensuring the next generation remains biodiverse Artificial insemination: This allows large numbers of offspring to be produced without the need for conventional sexual intercourse between males and females

Question 36

what are the risks to a species

Answer 36

If its population size decreases, a species will experience reduced genetic variation This renders the species more susceptible to environmental change The species is less resilient and has a greater risk of extinction

Question 37

Describe the negative consequences of letting untreated sewage flow into lake ecosystems

Answer 37

eutrophication -aquatic plants die as sunlight gets blocked -aerobic respiration of decomposers in the water reduce the amount of dissolved oxygen in the water -reduced amount of dissolved oxygen kills fish -food chain gets disrupted, more flies/mosquitos get habitats in or near the lake -visual pollution -toxicity caused by toxic or heavy metals polluting the water

Question 38

describe the effect of deforestation on the animals that live in forests

Answer 38

habitat destruction population decreases/migrates loss of biodiversity extinction disruption of food chain

Question 39

what causes populations to increase exponentially

Answer 39

birth rate greater than death rate no limiting factors few predators plenty of food

Question 40

Explain what happens to the energy that is absorbed by the vegetables but is not transferred to humans.

Answer 40

some plants are inedible eating by pests plants lose energy by respiration

Question 41

explain the likely consequences of an increase in the concentration of greenhouse gasses in the atmosphere

Answer 41

global warming increase in rate of photosynthesis causes an increase in plant growth/crop yield / vegetation reduced biodiversity

Question 42

how can sewage water be treated before entering a stream

Answer 42

screen sediment use microorganisms flocculate to make particles clump together and easier to separate chlorinate

Question 43

explain how can fish stocks can be conserved by restocking

Answer 43

captive breeding programmes release into protected areas monitoring no of fish limited fishing

Question 44

State the names of three natural processes involving bacteria that are important to ecosystems.

Answer 44

nitrogen fixing denitrifying fermentation

Question 45

explain the roles of bacteria in the filtration of water

Answer 45

secrete enzymes breakdown of insoluble substances to soluble substances breakdown of proteins to amino acids break down of glucose to starch break down fat to fatty acids and glycerol aerobic respiration using oxygen and carbon dioxide released