B19 - Human influences on ecosystems

Question 1

ecosystem definition

Answer 1

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

Question 2

biodiversity definition

Answer 2

the number of different species that live in an area

Question 3

what are 3 main reasons for habitat destruction?

Answer 3

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

Question 4

what are 5 undesirable effects of deforestation?

Answer 4

-reducing biodiversity
-extinction
-loss of soil
-flooding
-increase of carbon dioxide in the atmosphere

Question 5

what is an example of habitat destruction?

Answer 5

deforestation

Question 6

what are 6 reasons why a species might become endangered?

Answer 6

-climate change
-habitat destruction/loss of habitat
-hunting
-overharvesting
-pollution
-introduction of non-native / foreign / alien species

Question 7

endangered species can be helped by what 4 conservation measures?

Answer 7

-education (programmes)
-captive breeding (programmes)
-monitoring and legal protection of endangered species
-seed banks

Question 8

what are abiotic factors? give 5 examples

Answer 8

non living factors
-temperature
-oxygen
-CO2
-light intensity
-water availability

Question 9

what are biotic factors? give 4 examples

Answer 9

living factors
-predators
-food
-plants
-animals

Question 10

where would high biodiversity be found in an environment?[3]

Answer 10

lots of different species which show a lot of variation and are living in, all evenly distributed across the study area

Question 11

what are 3 human activities that are reducing biodiversity in ecosystems?

Answer 11

-waste production
-deforestation
-global warming

Question 12

what 3 things do you use to calculate relative biodiversity?

Answer 12

-number of different species in an area
-total number of individuals in an area in an ecosystem
-even spread/distribution

Question 13

if theres an even spread/distribution, what happens to the biodiversity?

Answer 13

increases

Question 14

what are 3 ways that reduce biodiversity?

Answer 14

-monoculture (farming)
-over harvesting
-climate change/global warming/pollution

Question 15

how does monoculture affect biodiversity?

Answer 15

theres a dominance of 1 species, not a variety, so biodiversity decreases

Question 16

describe monoculture

Answer 16

a field of one crop

Question 17

why are pesticides harmful to wildlife?

Answer 17

they don’t break down, they pass up the food chain and the pesticide level increases as it goes up the food chain

Question 18

where is the DDT stored in the organism?

Answer 18

fatty tissue

Question 19

what is biological control of pests?

Answer 19

using 1 species to control another - introducing foreign species sometimes

Question 20

what are 2 examples of increased land use?

Answer 20

-housing
-farming (crops for humans and farm animals and livestock)

Question 21

what are 4 effects of increased land use?

Answer 21

-uses valuable resources like space and water
-affects Earth’s atmosphere (more CO2 cause more respiration cause more animals)
-loss of biodiversity (monoculture)
-quality of soil decreases (loses minerals because all is used, so new crops don’t grow healthy)

Question 22

what are 5 examples of extraction of natural resources?

Answer 22

wood, stone, metal, gems, coal

Question 23

what are 5 effects of extraction of natural resources

Answer 23

-loss of habitat leads to loss of biodiversity
-disrupts food chains and webs
-could be extinction of some species
-increase in pollution and waste
-soil, air, and water quality reduced

Question 24

what are 5 examples of marine pollution?

Answer 24

oil spills, eutrophication, chemicals (toxins, carbon dioxide, agricultural waste

Question 25

what are 4 effects of marine pollution?

Answer 25

-ingestion -> animals may mistake plastic for food and eat it -suffocation -> animals may be trapped in plastic (nets) -carbon dioxide -> acidifies ocean and weakens the shell of animals with shells -oil spills -> toxic to eat, kills organism's food, blocks out light in water so organisms can't photosynthesis so they can't survive

Question 26

what is a example of freshwater pollution?

Answer 26

rubbish

Question 27

what are 4 effects of freshwater pollution?

Answer 27

-reduces water quality -chemicals may leak out of rubbish -causes sun blockage -spoils scenery (leisure and tourism)

Question 28

what are 4 effects of untreated sewage/fertilisers?

Answer 28

-excess fertilisers/animal waste run off into bodies of water -causes Eutrophication -causes algae blooms which block sunlight from reaching the water below which lead sto low oxygen levels and kills aquatic organisms

Question 29

what are 4 examples of chemical waste?

Answer 29

bioaccumulation, DDT, Mercury, Pesticides

Question 30

what are 5 effects of chemical waste?

Answer 30

-fertilisers lead to eutrophication -pesticides lead to bioaccumulation in organisms as they don't break down -kills organisms and their ability to reproduce -can make water murky so sunlight can't reach the lower levels which affects photosynthesis

Question 31

what are 2 effects of reducing biodiversity/extinction (deforestation)

Answer 31

-species go extinct so there are less animals -disrupts natural food chains

Question 32

what are 2 effects of loss of soil?(deforestation)

Answer 32

-harder fo rnew trees to grow because soil nutrients are lost -no tree roots to stabilize the soil so the soil is washed away into bodies of water

Question 33

what are 2 effects of flooding? (deforestation)

Answer 33

-trees slow down rain but because theres no trees, rain reaches ground directly -because there are no tree roots to stabilize the soil, the soil is easily washed away, causing landslides and flooding

Question 34

what are 2 effects of increased carbon dioxide concentration in the atmosphere?(deforestation)

Answer 34

-trees use carbon and release oxygen during photosynthesis but there are less tress so less organisms that are using carbon -trees are burned to destroy them but that the burning releases carbon (combustion)

Question 35

effect of climate change

Answer 35

all organisms have an ideal temperature range so if they can't adapt to a temperature change or other environmental condition fast enough, they could be endangered/go extinct

Question 36

effect of habitat destruction

Answer 36

as a species' habitat is destroyed, fewer of the organisms can be supported so the number starts to decrease and species could become endangered/extinct

Question 37

effect of hunting

Answer 37

many species are hunted for food, fur, and medicine but hunters may think endangered species are non-endangered and endangered species may be hunted to extinction

Question 38

effect of overharvesting

Answer 38

it disrupts food chains as the upper levels decreases for food loss and below levels increase for food gain. could lead to loss of sustainability, extinction, and loss of biodiversity

Question 39

effect of introduced foreign species

Answer 39

foreign species often thrive in their new environment and may become invasive. native species can't defend themselves again with invaders causing native species to die and foreign species to over populate as there are no native species to control the number of foreign species.

Question 40

what is monitoring and protecting endangered species

Answer 40

first monitor species numbers to identify endangered species, then protected areas are made to protect endangered species from threats such as hunting. (national parks, nature reserves -> development (building houses/farming) is restricted here allowing animals to be safe)

Question 41

what is education

Answer 41

teaching people about the natural world to help them understand the conservation and what they can do to help

Question 42

what is captive breeding programmes

Answer 42

animals are bred in captivity (zoos) and theres less infant death. some individuals are released into the wild to re-establish their population. there are certain factors that the animals need that the captive breeding programmes provide allowing the animal to reproduce easier.

Question 43

what are seed banks? why are they used?

Answer 43

the seeds of endangered plant species are kept in seed banks which have conditions necessary to keep seeds alive for along time. it protects and saves plant genetic diversity. seed banks are usually cold so that seeds don't germinate.

Question 44

formula for biomass

Answer 44

total mass of living material in an organism x the number of organisms

Question 45

what is accumulation?

Answer 45

pesticides that don't break down

Question 46

what is eutrophication caused by?

Answer 46

too much sewage or fertilisers (nitrate) is used so remainder is washed away