B18.1 - B18.12 - Biodiversity And Ecosystems✔️

Question 1

Define biodiversity?

Answer 1

Measure of the variety of all the different species of organisms on earth,or within a particular ecosystem - high biodiversity ensures the stability of ecosystems and reduces the dependence of one species on another for food,shelter an the maintaince of the physical enviorment

Question 2

Effects of humans using land and resources on ecosystems and the enviorment?

Answer 2

-more and more land used for building - houses,shops,industrial sites and roads - destroys habitats of living organisms and reduces biodiveristy

-we dig up vast areas to obtain rocks an metals ores - reducing the land available for other organisms

-waste we produce and release - destroys the enviorment and landfills use up lots of land affecting biodiversity

Question 3

How has rapid growth affected biodiveristy and the neviorment?

Answer 3

Increase in the population results in more land being needed for housing , more resources like food , non-renewable energys and more waste (for example bodily waste,rubbish from packaging and uneaten food) which all negativley affects the enviorment

Question 4

Issues with using pestecides and weedkillers (herbicides)?

Answer 4

These chemicals are poisons and when sprayed on the crops they also get in the soil - from there they can be washed into streams and rivers and become part of food chains , with the organisms not being able to break the toxins down ultimatley resulting in deaths for the top predators when dangrous levels of toxins build up

Question 5

How is more water being polluted?

Answer 5

Growing population means a growing need for food so more famers add ferteslisers to the soil resulting in minreals (like nitrates) from these fertelisers getting washed from the soil into local streams,ponds and rivers - untreated sewage washed int waterways also causes high levels of nitrates which stimulate the growth of algae and water plants

Question 6

How does increased pollution of nitrates impact rivers,ponds and streams negativly?

Answer 6

Nitrates stimulate the rapid growth of algae and other water plants resulting in the death of other plants due to the competition for light (and lack of photosynthesis)resulting in an increase of microorganisms feeding on the dead plants - microorganisms use up a lot of oxygen during respiration leading to a fall in levels of dissolved oxygen in water, so fish and other aquatic organims die and are decomposed by more microorganims using even more oxygen , until the pond becomes ‘dead’

Question 7

How is acid rain formend?

Answer 7

Burning of fossil fuels containg sulfure impurities react wth oxygen to form sulfure dioxide gas - acidic sulfure dioxie gas and nitrogen oxide dissolve in rainwater and react with oxygen in the air to form dilute sufluric acid and nitric acid

Question 8

Effects of acid rain on the enviroment - Land?

Answer 8

Acid rain can directly damage trees it falls on and kill the leaves,buds,flower and fruits aswell as this it can soak into the soil and destroy roots resulting in the destruction of whole ecosystems

Question 9

Effects of acid rain on the enviroment - water?

Answer 9

If acid rain falls into lake,rivers and streams the water them becomes slightly acidic and if the concentration gets to high it can no longer substain the life of plants and aquatic organisms - resulting in the body of water becoming ‘dead’

Question 10

Effects of acid snow on the enviorment?

Answer 10

The acid falls as snow which can be more dangrous as all the acid is released in the first meltwater of spring which causes and ‘acid flush’ which magnifies the effects of acid rain,producing water with a verly low pH

Question 11

How has the UK and other countries tried to stop vehicles,factories and power station producing acidic gases?

Answer 11

-low sulfur and diesel used in vehicles

-catalytic convertes are fitted to remove polluting gases from the exhaust fumes

-low-sulfur fuels have beein introduced like gas in power stations

-systems put in place to clean the flue gases before they are released into the enviorment

Question 12

Effects on the enviorment from smoke pollution?

Answer 12

Smoke pollution causes an increse in the number of tiny solid particles called particulate in the air - which reflect sunlight so less light hits the surface of the earth , cooling the temperatures at the surface

Question 13

What is smog?

Answer 13

Form of air pollution result of smoke and chemicals like sulfur dioxide and nitrogen oxides - forms a haze of small particles and acidic gases see in the air over major cities like China

Question 14

Main Reasons for deforestation?

Answer 14

-clear land for farming of crops that can be used to make biofuels

-to rear more cattle, particulary for the beef market

-to grow staple food such as rice, or ingridients for making cheap food in the devloped world such as palm oil

Question 15

Issues with ‘slash and burn’ method for deforestation?

Answer 15

Clearing trees for space is often done by ‘slash and burn’ where the trees are felled and burnt so no wood is collected just burnt

Question 16

How does deforestation releases carbon dioxide into the atmosphere - give 2 ways ?

Answer 16

-burning the trees leads to an increase in carbon dioxide levels from combustion seen with “slash and burn” method

-after deforestation the dead vegetation decomposes and microorganisms use up oxygen and release more carbon dioxide as the respire

Question 17

Why does deforestation result in a reduced rate at which carbon dioxide is removed from the atmosphere?

Answer 17

Trees and other plants use carbon dioxide for photosynthesis and will take it from the air and it gets locked up for years so when we destroy the trees we lose a vital carbon dioxide ‘sink’ - dead trees also decay releasing more carbon dioxide

Question 18

How does deforestation reduce biodiveristy?

Answer 18

Loss of forest habitat and plants that the animials eat results in many dying and becomig extinct

Question 19

What is Peat and why can it not decay?

Answer 19

Peat is made of plant material that cannot decay completely because the conditions are very acidic and lack oxyen

Question 20

What are peat bogs?

Answer 20

Bogs are very wet areas of land without trees in which many types of moss grow. They are acidic and often have very low levels of nutrients. Here decomposition is very slow and peat is formed from partially decayed plants - which act as massive carbon stores

Question 21

Uses of Peat?

Answer 21

-burnt as fuel

-used by gardners to improve the properties of the soil and provide an ideal enviorment for seed germination

Question 22

Issues with peat being burnt?

Answer 22

When peat is burnt or used in gardens, carbon doxide is released into the atmosphere and the carbon store is lost - peat is formed very slowly so it is being destroyed faster than it is made

Question 23

Explain the greenhouse effect?

Answer 23

Energy from the sun reaches the earth , warming it up and much of it is radiated back out into space however gases such as carbon dioxide and methane in the atmosphere absorb some of the energy transferred as the earth cools down , as a result the earth and its surrrounding atmosphere are kept warm and ideal for life

Question 24

3 Consequences of climate change an rising sea levels?

Answer 24

-loss of habitat reuslting in a decrease in biodiversity

-change in distribution - as temperature rise or fall and rainfall patterns change it might make conditions favourable for some animials and they may be able to extend there range

-change in migration patterns - climate becomes coler ot hotter and seasons change migration patterns of bugs and insects may also change

-loss of biodiveristy - if the artic ice melts animials liek polar bears may die

Question 25

How does seasonal changes effect and change in the distribution of organisms?

Answer 25

Temperature, amount of rainfall, availability of water and hours of daylight vary dramatically between the seasons in different parts of the world and so does the distribution of plants and animials for example some migrate to aviod the cold while others only appear when conditions are favourable

Question 26

How does geographical changes effect and change in the distribution of organisms?

Answer 26

Changes in factors like soil structure or pH, altitude, saltiness of water, and availability of water - many animals and plants have specific adaptions to enable them to survie and reproduce in particular geographical conditions

Question 27

How does human interaction effect and change in the distribution of organisms?

Answer 27

Many enviormental changes are the result of human activities and these changes can have big effects on the distribution of organisms in an area examples include: global warming / climate change, effects of acid rain, pollution from farms and factories

Question 28

What are breeding programs and how do they work?

Answer 28

Can restore an endangered species to a sustainable population but it is difficult as many rare animials and plants do not reproduce easily or fast enough and artificial breeding programs come with the risk of inbreeding which has to be avioded - animials can be released back into their natural habitasts when they are safe again

Question 29

What are trophic levels?

Answer 29

The positions of organisms within a food chain are known as trophic levels

Question 30

What is trophic level 1?

Answer 30

Producers - make their own food by photosynthesis eg plants and algae

Question 31

What is trophic level 2?

Answer 31

Primary consumers - herbivores that eat plants and algae

Question 32

What is trophic level 3?

Answer 32

Secondary consumers - carnivores that eat herbivores

Question 33

What is trohpic level 4?

Answer 33

Tertiary consumers - carnivores that eat other carnivores - apex predators

Question 34

What are apex predators?

Answer 34

Carnivores with no predators and are found at the top of the food chain

Question 35

What are decomposers?

Answer 35

Decomposers break down dead plant and animial matter by secreting enzymes into the eneviorment - small soluble food molecules difduse back into microorganism down a concentration gradient

Question 36

Define biomass?

Answer 36

Mass of material in living organisms - wet biomass in grams can be used because it does not involve killing the organism and drying them out however it is not as usefull because amount of water in an organism changes throughout the day

Question 37

What is often the original source of biomass?

Answer 37

Usually photosynthesis made by plants and passed on throuugh food chains and food webs by animials eating other animials

Question 38

3 reasons why the amount of biomass in the organisms is less than it was at the previous level?

Answer 38

-not all parts of the organism are eaten for example plant roots or animial bones may be left behind

-some biomass taken in is lost in waste material for example faeces

-large amounts of biomass taken in is used in respiration to transfer energy for the organismsand only a relativley small proportion is used to build new biomass in the organisms at the next trophic level

Question 39

Why are pyramids of biomass constructured?

Answer 39

Can represent the relative amount of biomass at each level of the food chain - trophic level 1 is always at the bottom of the pyramid

Question 40

What is incident enegry?

Answer 40

The energy from light falling on the earth with only about 1% being used by plants and algae for photsynthesis however it is enough to provide biomass for all other organisms

Question 41

Approximately how much biomass from each trophic is transferred to the level above it?

Answer 41

Only about 10% of the biomass from each trophic level is transferred the the level above it

Question 42

Why can not all the biomass be digested by herbivores?

Answer 42

Herbivores cannot digest all the plant material they eat because most herbivores do not have enzymes needed to digest cellulose - and so large amounts of plant biomass cannot be broken down and absorbed so this material is passed out the body as faeces - which is eventually broken down by the decomposers

Question 43

Why is it easier for carnivores to take in more biomass on average then herbivores?

Answer 43

Carnivores mianly eat meat and therefore protein so it is much easier to digest then what the herbivores eat so they need to eat less often then herbivores and produce less waste however they can not digest all the parts of their prey for example hooves,claws or bones and some biomass is also lost as faeces

Question 44

Why do mammals and birds need to eat more food than animials such as fish and amphibians to achieve the same increase in biomass

Answer 44

Mammals and birds warm their surroundings because the breakdown of biomass in respiration which transfers energy to the surroundings - this happens all the time because mammals and birds need to keep there body at a constant temperature so they need to eat more food

Question 45

What are some of the waste products biomass is lost as?

Answer 45

Some absorbed material is lost as carbon dioxide and water in respiration and water and urea in urine aswell as large amounts of glucose used in respiration

Question 46

Four factors affecting food security?

Answer 46

-increasing birth rates
-conflict affecting access to water or food
-new pests and pathogens
-changing diets in developing countries - means scarce food resources and transported around the world

Question 47

What is food security?

Answer 47

Having enough food to feed a population

Question 48

Two ways famer can get the maxium possible increase in biomass from animials?

Answer 48

-limiting the movment of food animals so they do not used their musscles much which reduced the need for respiration

-controlling the temperature of the surroundings to the animials do not have to use much biomass in respiration for keeping warm or cooling down

Question 49

What can animials be fed for increased growth?

Answer 49

High protein foods - eg fish in fish farms are fed ground up wild caught fish or cereals that could have been used for human food

Question 50

2 ways we can manage the oceans?

Answer 50

-controlling the size of the holes in nets - allows for smaller fish to escape and grow large enough to breed so only the large fish are caught

-strict quotas imposed on fishermen - their can be bans on fishing in the breeding season and the type of fish they can catch

Question 51

Why are fish stocks in the ocean declining?

Answer 51

Overfishing as a result of massive modern ships has meant huge quantities of fish are caught so people fish for smaller younger fish but there are no more breeding animals to replace them

Question 52

How can genetically modified crops help solve food problems?

Answer 52

They can give bigger yeilds or improved nutrition for example goldren rice which gives extra vitamin A

Question 53

Why is the funguss Fusarium useful?

Answer 53

Used for producing mycoprotein, a protein rich food suitable for vegetarians

Question 54

What is Fusarium?

Answer 54

Fungus which grows and reproduces rapidly on relativley cheap glucose syrup, in large specialised containers called fementers - needs aerobic conditions to grow successfully - it is then harvested and purified

Question 55

How can genetically modified bacteria be used?

Answer 55

Can be used to produce drugs such as insulin on an industrial scale