[Part 2]- B17- Biodiversity and ecosystems ♻️

Question 1

What is a pesticide ?

Answer 1

• a pesticide, is a chemical compound used to kill pests [and is typically used in agriculture.]

Question 2

What’s a herbicide ?

Answer 2

• a herbicide, is a chemical compound use to kill unwanted plants or weeds.

Question 3

What’s a fertiliser ?

Hint: the soil

Answer 3

• a fertiliser, is a substance that is added to the soil in order to increase the productivity [growth] of plants

Question 4

What’s the difference between a pesticide 🆚 a herbicide 🆚 a fertiliser?

Answer 4

• a pesticide, is a chemical compound used to kill pests [and is typically used in agriculture.]
• ; herbicide, is a chemical compound use to kill unwanted plants or weeds.
• and a fertiliser, is any substance that is added to the soil in order to increase the productivity (growth of plants).

Question 5

How can pesticides affect water ?

Answer 5

• pesticides can cause:
• eutrophication
• and, bioaccumulation in aquatic food chains

Question 6

How can fertilisers pollute water ?

Hint: nutrients

Answer 6

• Fertilizers are made of nutrients, such as nitrogen and phosphorus.
• these fertilisers can pollute the water because, when it rains, these nutrients are carried by water into the nearest stream, river, or other water body.
• ; Too many nutrients in the water can cause algae to grow, which uses up the dissolved oxygen in the water.

Question 7

How can pesticides, pollute the land ?

Hint: contaminate

Answer 7

• pesticides can contaminate the soil- which has significant impacts throughout the ecosystem.
• This is because pesticides can also linger in the soil for years after they are applied, continuing to harm soil health.

Question 8

Describe how herbicides pollute the land and water.

Answer 8

• herbicides can cause the average CO2 concentration in pond water to increase.
• This is because, carbon dioxide dissolves in water to produce carbonic acid.
• and if the pond becomes more acidic, this impact the productivity of plants in the pond, since it decreases growth and ultimately, impacting the food webs within the pond.

Question 9

How can ubbish pollute water ?

Answer 9

• rubbish can pollute water because, species can ingest it or become entangled by plastic debris- which can cause severe injuries and death

Question 10

Describe the process of eutrophication

Answer 10

1) Sewage or fertiliser run-off increases the nutrient concentration of the water.

2) these extra nutrients cause increased growth of the aquatic plants/algae – this is known as an algal bloom.

3) The algal bloom then covers the water’s surface and kills any plants below the surface because light and oxygen cannot reach them.

4) Algae will then die as the nutrients run out.

5) Aerobic bacteria will decompose the dead plants.

6) the Bacteria will them use up oxygen for respiration.

7) and finally, Fish and other organisms will die from a lack of oxygen.

Question 11

Describe the processes of bioaccumulation,

Answer 11

• Toxic chemicals, such as pesticides, can also be washed into waterways.
• They then become part of the food chain.
• The toxins get into the organisms that feed on plants.
• These poisons sit in the tissue of these organisms, so when they are eaten by their predator, the toxin gets passed on.
• As you move up the food chain, the concentration of toxin in each trophic level increases until the top predator has extremely toxic concentrations.

Question 12

Explain in detail how pollution affects biodiversity.

Answer 12

• • pollution can affects biodiversity because:*
• Humans will produce waste, and as the human population increases, more waste will be generated.
• ; If this waste is not handled properly it can become a pollutant of land, water and air. For example, humans produce a large amount of sewage.
• and in the UK, sewage is treated before being released ; in some cases, untreated sewage can accidentally be released into rivers or streams.
• This can cause water pollution because large [and excess] amounts nutrients, are introduced into the water. [e.g- nitrogen and phosphorous.]- killing animals and plants, which therefore reduces biodiversity. [due to pollution]

Question 13

Explain how pesticides in water, can kill top predators in food chains.

Answer 13

• pesticides in water can kill top predators in food chains, because of bioaccumulation.
• this is because animals tend to eat lots of organisms from the level below in food chains.
• and therefore the concentration of pesticide in the bodies of organisms, will increase at higher levels of food chains.
• which can kill top predators because, this can result in the toxicity of the pesticide, reaching fatal levels at the top of the food chain.

Question 14

What is the difference between bioaccumulation 🆚 eutrophication?

Answer 14

• Bioaccumulation is the build-up or accumulation of toxins, in a food chain.
• ; Eutrophication, is the process by which a body of water becomes enriched with nutrients, leading to excessive growth of algae and other aquatic plants.

Question 15

What are some effects of acid rain, on plants and animals ?

Answer 15

• acid rain kills plant life. For example, acid rain can cause phytoplankton [a plant] in lakes to die.
• these means that insects, which rely on phytoplankton for food, now have less food to eat= they begin to die
• acid rain also kills aquatic life ; it also removes minerals and nutrients from the soil, that trees need to grow.

Question 16

Describe how acid rain is formed

Answer 16

• Fuels are first burned to produce energy.
• and since all fossil fuels contain a small amount of sulphur, when these fuels burn, the sulphur turns into sulphur dioxide.
• Sulphur dioxide and nitrogen oxides pour into the air from: homes, factories and cars and sulphur dioxide gas is then carried high into the air.
• The gas dissolves into rain drops and makes acid rain, which then falls, destroying buildings and killing animals and plants.

Question 17

Explain what causes smog, and describe their effects

Answer 17

• smog is caused by particles in the air, combining with a chemical compound, known as ozone.
• it can cause: difficulty in breathing, asthma, reduced resistance to lung infections, colds, and eye irritation because

Question 18

What’s the word equations, to show how burning some fuels produces acidic gases.

Answer 18

• The formation of acid rain, [ by sulphur dioxide or nitrogen oxides, requires a series of reactions.]
• ; these reactions can be simplified to word equations:
• Sulphur dioxide + water—-> Sulphuric acid (in water)
• Nitrogen oxides + water——> Nitric acid (in water)

Question 19

Explain what causes global dimming and describe their effects

Answer 19

• global dimming, is the gradual reduction in the amount of light reaching the Earth’s surfac
• it can be caused by too many particulates in the air, mixing with chemicals, to form a mixture of acidic gases and small particles.
• and because of Global dimming, less light can reach the Earth; it can also directly affect human health.
• since its believed that it may damage cells in the lungs and cause lung cancer.
• ; it’s also though to affect the cardiovascular system (heart).

Question 20

What are the effects of global dimming ?

Answer 20

• less light can reach the Earth; it can also directly affect human health.
• since its believed that it may damage cells in the lungs and cause lung cancer.
• ; it’s also though to affect the cardiovascular system (heart).

Question 21

Plan an investigation to find out how acid rain affects the germination of seeds. 🌱

Answer 21

1) Place some cotton wool in a petri dish, and then Pour 20ml of distilled water into a beaker, using a measuring cylinder.

2) then placethe cotton wool in the petri dish, pouring the 20mls of the distilled water, and spread a 20 seeds evenly over.

3) Replace the lid on the petri dish and label it as distilled water.

4) Pour 19ml of distilled water into the beaker and add a further 1ml of 1mol/dm3 sulphuric acid and stir well.

5) Pour over a second piece of cotton wool in a new petri dish and spread 20 seeds evenly over.

6) Replace the lid and label 10% Acid Rain, then repeat this process using the different concentrations of sulphuric acid.

7) overall, there should be have 5 tests in total= [Distilled, 10%, 5%, 1% and 0.1%].

8) Put the petri dishes in a warm and dark place, for a few days, until they germinate, and finally count the number of germinated seeds, in each petri dish.

Question 22

How can pesticides pollute water ?

Answer 22

• pesticides can contaminate ground water and freshwater supplies

Question 23

• Fill in the gaps: acid rain can dissolve nutrients, [e.g-magnesium and calcium] that trees need to be _______

Answer 23

• acid rain can dissolve nutrients, [e.g-magnesium and calcium] that trees need to be healthy.