Unit 20

Question 1

how have humans used agricultural machinery to produce more food

Answer 1

increases efficiency and larger areas of land is used

Question 2

how have humans used chemical fertilizers to produce more food

Answer 2

increases crop yields

Question 3

how have humans used insecticides

Answer 3

increases crop yields and food quality

Question 4

why do humans use herbicides

Answer 4

reduces number of weeds

Question 5

why do humans use selective breeding

Answer 5

improves production of livestock and crops

Question 6

what is monoculture

Answer 6

one variety of crop is grown at a time

Question 7

disadvantages of monoculture

Answer 7

reduced biodiversity in the area
diseases can spread easier which leads to more insecticides
soil is damaged since nutrients are used up and soil will erode
increased fertilizers and insecticides causes pollution

Question 8

advantages of monoculture

Answer 8

allows farmers to use machinery and increases efficiency
easier to manage
takes advantage of certain weather conditions

Question 9

advantages of intensive livestock production

Answer 9

produces high amounts of food for growing human population
efficiency increases while costs decrease

Question 10

disadvantages of intensive livestock production

Answer 10

impacts the animals wellbeing and health
impacts the environment(pollution)
disease can spread quickly

Question 11

what is biodiversity

Answer 11

the number of different species living in an area

Question 12

what are reasons for habitat destruction

Answer 12

increased area for housing, crop production and livestock
extraction of natural resources
freshwater and marine pollution

Question 13

how can humans have a negative impact on negative habitats

Answer 13

through altering food webs and food chains

Question 14

what is deforestation

Answer 14

the cutting down of trees in forests

Question 15

what can deforestation lead to

Answer 15

flooding
loss of soil
extinction of species
increase in carbon dioxide in the atmosphere

Question 16

what is flooding(deforestation)

Answer 16

trees hold soil together and when theyre gone soil is washed away

Question 17

what is loss of soil (deforestation)

Answer 17

when large areas are cleared, the protective layer of vegetation is lost
soil is then blown away by wind or rain

Question 18

what is extinction (deforestation)

Answer 18

animals may be forced to migrate or stay in the area where they struggle to find food and shelter since the habitats are destroyed

Question 19

what is carbon dioxide(deforestation)

Answer 19

with trees gone, photosynthesis cannot occur and carbon dioxide is not converted to carbohydrates

Question 20

what is pollution

Answer 20

the release of any substance that has a toxic effect on the environment

Question 21

what is the effect on untreated sewage and excess fertilizer in aquatic ecosystems

Answer 21

causes eutrophication and pollutes waterways that kills fish and plants while also endangering human life

Question 22

what are the effects of non biodegradable plastic on aquatic ecosytems

Answer 22

cases suffocation and entanglement of marine wildlife and can cause starvation of fish
can also affect humans

Question 23

what are the effects of non biodegradable plastic on terrestrial ecosystems

Answer 23

causes soil destruction and animal deaths
can also infect humans with harmful chemicals

Question 24

how does air pollution affect the nevironment

Answer 24

leads to the greenhouse effect due to methane and carbon dioxide and climate change as the earth gets warmer

Question 25

what is eutrophication of water

Answer 25

fertilizer leaks into waters increases growth of producers leads to increased decomposition and blocking of sunlight reduced oxygen death of organisms such as plants and marine life due to loss of oxygen

Question 26

what is a sustainable resource

Answer 26

one which is produced as rapidly as its removed from the environment

Question 27

what resources can be conserved and managed sustainably

Answer 27

forests and fish stocks

Question 28

reasons for endangerment or extinction of organisms

Answer 28

climate change habitat loss hunting overharvesting pollution introduction of new species

Question 29

how can endangered species be conserved

Answer 29

monitoring of protected species and habitats education captive breeding programs seed banks

Question 30

how can forests be conserved

Answer 30

education protected areas quotas replanting

Question 31

how can fish stocks be conserved

Answer 31

education closed seasons protected areas controlled net types and mesh size quotas and monitoring

Question 32

what are the reasons for conversation programmes

Answer 32

maintaning or increasing biodiversity reducing extinction protecting vulnerable ecosystems maintaining ecosystem functions

Question 33

what is artificial insemination and IVF used for in captive breeding programmes

Answer 33

increases populations of organisms and reduces endangered species

Question 34

what are the risks to a species if population size decreases

Answer 34

reducing genetic variation in he species and leads to extinction