Topic 9 : Ecosystems and Material Cycles

Question 1

What are the levels of organisation in an ecosystem?

Answer 1

Organism → Population → Community → Ecosystem.

Question 2

What are the levels of organisation in an ecosystem?

Answer 2

Organism → Population → Community → Ecosystem.

Question 3

What is an organism?

Question 4

What is an organism?

Answer 4

A single living thing, e.g. a fox.

Question 5

What is a population?

Question 6

What is a population?

Answer 6

A group of the same species living in the same area, e.g. a group of foxes.

Question 7

What are biotic factors?

Answer 7

Living parts of the ecosystem (animals, plants, bacteria) that affect other organisms e.g. competition for resources, predation, amount of disease and availability of food

Question 8

What are abiotic factors?

Answer 8

Non living parts of an ecosystem that affect other organisms e.g. light intensity, temperature, moisture, oxygen levels, pollutants, soil conditions and wind conditions

Question 9

What are biotic factors?

Answer 9

Living parts of the environment that affect other organisms

Question 10

What is a community?

Answer 10

All the different species living and interacting in an area, e.g. foxes, rabbits, trees, insects.

Question 11

What is an ecosystem?

Answer 11

All the living organisms (community) and non-living (abiotic) factors in an area.

Question 12

How can biotic factors affect a community?

Answer 12

Biotic factors like competition and predation affect population sizes and interactions.

Question 13

How can abiotic factors affect a community?

Answer 13

Abiotic factors like temperature, light, water, and pollutants can change survival and reproduction rates.

Question 14

How can abiotic factors affect a community?

Answer 14

Abiotic factors like temperature, light, water, and pollutants can change survival and reproduction rates.

Question 15

Why is interdependence important in a community?

Answer 15

Species rely on each other for things (food, shelter, pollination, etc) and disruption of this affects the whole community.

Question 16

What is mutualism?

Answer 16

When both organisms benefit from a relationship e.g. flowering plants and bees -> bees get nectar to eat and plants pollen gets spread so other plants can get fertilized

Question 17

What is parasitism?

Answer 17

Parasite lives inside or on the host. Parasite benefits by getting food or habitat while host gains nothing and is often harmed by the relationship e.g. tapeworms in humans benefits by absorbing nutrients but this could cause host to lose weight or get ill

Question 18

What fieldwork techniques are used to study organisms and their environment?

Answer 18

Quadrats and belt transects are used to measure distribution and abundance.

Question 19

What are at the first and bottom trophic level of a food chain?

Answer 19

Producers: plants or algae that make their own food

Question 20

What is the order of trophic levels in a food chain?

Answer 20

Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer → Apex Predator.

Question 21

What is biomass?

Answer 21

The total mass of living material at a particular trophic level in a food chain. The lower the biomass, the less living organisms.

Question 22

Why is energy transfer between trophic levels inefficient?

Answer 22

Energy is lost as heat, movement, or waste , between trophic levels, limiting the food chain length. Only about 10% is passed on to the next level.

Question 23

How do you calculate energy transfer efficiency?

Answer 23

Efficiency (%) = (Energy transferred ÷ Total energy available) × 100.

Question 24

What is a food chain?

Answer 24

Are diagrams that show the energy flow between organisms in an ecosystem.

Question 25

What is biodiversity?

Answer 25

The variety of living organisms in an ecosystem

Question 26

Why is biodiversity important for keeping ecosystems stable?

Answer 26

In more biodiverse ecosystems, there are more species meaning that means that organisms have more options for food and shelter. However if there are less species that animals could be more dependent on a smaller amount of options meaning they could run out of food.

Question 27

What are the benefits of maintaing biodiversity?

Answer 27

Protecting the human food supply, ensuring minimal damage to food chains, providing future medicines, cultural aspects (national symbols like USA bald eagle), ecotourism and providing new jobs (ecotourism, conservation schemes and reforestation schemes)

Question 28

How does fish farming affect biodiversity?

Answer 28

It can reduce biodiversity by reducing the number of wild fish and through disease spread (large number of fish together can cause parasite breeding) and can kill predators if they get trapped in nets.

Question 29

What are the effects of introducing non-indigenous species?

Answer 29

They may outcompete native species and reduce biodiversity e.g. non indigenous rabbits could breed quickly and could threaten native plants and compete with native animals for food and shelter

Question 30

How can introducing non-indigenous species accidentally affect an ecosystem

Answer 30

Could reduce biodiversity e.g. zebra mussels carried to European waters on bottom of ship -> reproduce very quickly and are good at filtering out plankton -> native species that eat plankton have no food.

Question 31

What is eutrophication and how does it affect ecosystems?

Answer 31

Nitrates from fertilizer runoff causes algal blooms, covers surface of water, blocking light, plants can't photosynthesis so die and decompose, depleting oxygen and killing aquatic life as they need it to live.

Question 32

What is reforestation and how does help biodiversity?

Answer 32

Replanting plants in past forest areas replaces lost habitats and supports a variety of species.

Question 33

What biological factors affect food security?

Answer 33

Population growth, more meat consumption, new pests/pathogens, environmental changes, and biofuel use.

Question 34

What is food security

Answer 34

Having enough food to feed a population

Question 35

What factors affect food security?

Answer 35

Increasing consumption of meat and fish and animal farming -> more expensive, less energy, less biomass, enviromental changes caused by human activity (burning fossil fuels), sustainability and new pests and pathogens -> can cause damage to crops or livestock

Question 36

How does water get in the atmosphere as water vapour?

Answer 36

Heat energy causes water to evaporate and transpiration in plants

Question 37

How does water vapour form clouds in the sky

Answer 37

Condensation - water cools and condenses as it rise