Ecology

What is biodiversity?

Variety of different species on Earth

Why is higher biodiversity important for ecosystems?


It leads to more stable ecosystems

How does higher biodiversity reduce dependency among species?

Species rely on multiple other species

What happens if one species is wiped out in a biodiverse ecosystem?


Other species can survive due to alternatives

What are the main strategies to maintain biodiversity?

• Breeding programs for endangered species

• Protection and regeneration of rare habitats

• Reduction of deforestation and CO2 emissions

• Recycling resources instead of dumping waste

What role do microorganisms play in peat bags?

• Help to decay plants

• Facilitate the breakdown of organic matter

What is the consequence of insufficient oxygen in waterlogged soil?


Not enough oxygen for aerobic respiration

How does peat contribute to carbon storage and release?

Stores carbon and releases carbon dioxide

What is the consequence of peat bog destruction?

• releases CO2 and methane

• burning releases CO2 into atmosphere

• increase in greenhouse gases

• increases temp of earth’s atmosphere

• (reduces the area of this habitat thus the variety of different plant, animal and microorganism species that live there)

• Why do dead plants not decay deep below surface peat bogs

contains very little oxygen

microorganisms won’t have enough oxygen to aerobically respire

therefore they have less/no energy to break down dead remains of plants

or

low pH denatures enzymes

less metabolic reactions

in microorganisms

What is the impact of waste management on biodiversity?


Poor waste management reduces biodiversity

How can chemicals from waste affect the environment?

They can poison the soil and water

What is one reason for managing waste effectively?

To prevent environmental contamination

How does household waste contribute to environmental issues?

It adds to landfill and pollution problems

What is a consequence of increased waste production?

More landfill sites are needed

What is the effect of acid gases from factories?

They contribute to air pollution

What is one method to manage waste effectively?

Recycling and proper disposal

What can be a side effect of improper waste management?

Contamination of natural resources

What is the significance of managing waste in urban areas?

It prevents health hazards and pollution

What is the consequence of rapid growth of the human population?

an increase in the standard of living which mean that increasingly more resources are used and more waste is produced.

What is the purpose of breeding programs for endangered species?

• To restore a sustainable population

  as many rare plants and animals don’t reproduce fast

What is the process of breeding programs?

• brees in zoos with genetics of each animal carefully recorded

• then released back into the wild

• only released when their natural habitats are safe again

How does deforestation affect biodiversity?

• there will be less trees to take in carbon dioxide through photosynthesis

• large release of carbon

• pollutes towns & suffocates animals

• reduces biodiversity entire species become extinct

Methane

1.Microorganisms fermenting in cattle

2.Decomposition in landfill sites

3.Bacteria fermenting in paddy fields

Carbon Dioxide

• Recent rise in CO₂ has occurred due to use of fossil fuels

• Deforestation has caused a decreased uptake of CO₂ by photosynthesis

• Raised levels of CO₂ has led to global warming

Water vapour

• Water vapour is the most dominant greenhouse gas

• not the reason for raising the Earth’s temperature

• acts as an amplifier of the Earth’s increasing temperature

The Greenhouse effect

• The Sun emits shortwave radiation.

• Some of the rays are reflected by the Earth as long wave radiation

• Greenhouse gases causes the long wave radiation to be re-emitted to the Earth

What is the impact of climate change on species migration?

Species move to the poles to escape rising temperatures

How does global warming affect sea levels?


Sea levels rise due to melting ice

What is a potential consequence of changing seasons due to climate change?

Altered patterns in food availability

What is the role of microorganisms in ecosystems?

They help decompose organic matter

How does agricultural practice affect biodiversity?

It can lead to habitat loss and pollution

What is the significance of maintaining pH levels in farming?

It ensures optimal growth conditions

What are the consequences of food scarcity in developing countries?


• Increased hunger and malnutrition

• Economic instability

• Social unrest and conflict

• Dependence on food aid

What is the relationship between food supply and population growth?

Food supply must meet population demands

How do changing diets affect food production?

They require adjustments in agricultural practices

What does " Overfishing" refer to?


Catching too many fish

What is the impact of overfishing on fish populations?

• It reduces fish species and affects food chains

Why is it important to maintain fish species at sustainable levels?

To ensure fish can continue to breed

What are the methods to maintain fish species sustainably?

• Quotas on number and size of fish caught

• Restrictions on net size

• Use of larger mesh sizes to reduce bycatch

What do quotas in fishing refer to?

Limits on number and size of fish caught

How do quotas prevent overfishing?

By limiting the catch of certain species

What is the purpose of net size regulations in fishing?

To reduce the number of unwanted fish caught

Why is using larger mesh sizes beneficial in fishing?


It allows unwanted species to escape

How do fishing quotas and net size regulations work together?

They both help prevent overfishing and bycatch

What biological factors threaten food security?

• the increasing birth rate has threatened food security in some countries

• changing diets in developed countries means scarce food resources are transported around the world- therefore scarce food becomes scarcer

• new pests and pathogens that affect farming- antibiotic resistant pathogens and pests that have evolved to pesticides

Farming Techniques

To make food production more efficient.

• Limiting the movement of livestock and keeping them in a temperature-controlled environment reduces the transfer of energy

• more energy is available for growth, so more food can be produced from the same input of resources

Examples

• Livestock like calves and chickens can be factory farmed. This involves raising them in small pens.

• Fish can also be factory farmed in underwater cages where their movement is restricted.

• Some animals are also fed high-protein food to further increase their growth.

Why is more land used for farming?

• to grow crops and livestock

• population is increasing so food supply must meet population demand

How has farming decreased biodiversity?

• land is cleared out for farming which leads to loss of habitat

• endangered species which decrease biodiversity

• causes deforestation

• releases carbon from trees which increases amount of CO2 in atmosphere contributes to global warming

• animals and plants may not be able to survive in conditions

Biotechnology

• As population increases, need to find new food sources to add to those now

• modern food source that is becoming popular is mycoprotein.

• A fungus called Fusarium is the main source of mycoprotein. It is grown in large vats on glucose syrup, which acts as food for the fungus.

• The fungus respires aerobically, so oxygen is supplied, together with nitrogen (as ammonia) and other minerals.

• The mixture is also kept at the right temperature and pH. Once ready, the fungal biomass is harvested, purified and dried to make the mycoprotein.

• It's then processed further by adding flavourings and other ingredients.

What is a mycroprotein?

• Mycoprotein means protein from fungi. It's used to make high-protein meat substitutes for vegetarian meals, e.g. QuornTM.

Adv and disadv of GM crops

Benefits	Problems
can increase the amount of food that a crop provides (its yield)	Many people argue people go hungry because they can't afford to buy food, not because there isn't any food about.
People living in developing countries often lack nutrients in their diet.	argued that you need to tackle poverty first.
E.g 'golden rice' has been engineered to produce a chemical that's converted in the body into vitamin A	It might reduce/abolish the use of normal rice and make people go out of business
crops can be produced that are resistant to pests or are able to grow better in drought conditions.	fears that countries may become dependent on companies who sell GM seeds.
can improve flavour & shelf life	don’t know long term effects on health

Fish exchange gases through gills

Oxygen from water enters the blood of a fish through gills.

Explain how gills are adapted to maximise the exchange of oxygen between water and blood. (4)

• Gills/capillaries have very thin walls to allow for a short diffusion pathway (water proximity close to blood)

• good blood supply to maintain concentration gradient

• large surface area for gas exchange/ maximum diffusion