Topic 7 - Ecology

Question 1

Define community.

Answer 1

Populations in an area.

Question 2

Define ecosystem.

Answer 2

The interactions between living and non-living parts of an area.

Question 3

Define interdependence.

Answer 3

How species in a community depend on each other for things like food, shelter, pollination etc.

Question 4

Define stable ecosystem.

Answer 4

Stable ecosystems have balanced environmental conditions and constant species numbers.

Question 5

What is intraspecific competition?

Answer 5

Competition between members of the same species.

Question 6

What is interspecific competition?

Answer 6

Competition between members of different species.

Question 7

What are abiotic factors and give some examples.

Answer 7

Abiotic - Non-living factors that can affect the numbers of species in population in an ecosystem.
For example light intensity, temperature, water availability, carbon dioxide concentration, oxygen level, soil ph and mineral content, wind intensity

Question 8

What are biotic factors and give some examples.

Answer 8

Caused by living organisms that can affect the size of populations in an ecosystem.
Examples, new predators, new pathogens. Amount of food, competition.

Question 9

Define adaptations.

Answer 9

Features organisms have to allow them to survive in their environment.

Question 10

What are the 3 types of thing adaptations can be?

Answer 10

Structural - Long roots, thick fur.
behavioural - Living in burrows
functional - Produce toxins.

Question 11

Some microorganisms are known as extremophiles, what is that?

Answer 11

Adapted to live in extreme habitats.
Mostly bacteria from archaea.

Question 12

What are the apex predators known as in a food chain?

Answer 12

Tertiary consumers.

Question 13

What is the carbon cycle?

Answer 13

The process by which carbon is continuously recycled through living organisms and the environment.

Question 14

What process returns carbon dioxide to the atmosphere?

Answer 14

Respiration of plants, animals, and decomposers
Combustion of fossil fuels or wood
Decay

Question 15

What is the role of microorganisms in the carbon cycle?

Answer 15

They decompose dead organisms, breaking down carbon compounds, and release CO₂ via respiration.

Question 16

Describe the stages of the water cycle.

Answer 16

1) Evaporation - Water evaporates from large volumes such as ocean, and trees from transpiration.
2) Condensation - condenses and cools down in the clouds.
3) Precipitation - falls from clouds as rain sleet or snow.

Question 17

What are decomposers?

Answer 17

Bacteria and fungi that break down dead, living material or waste from animals to release small molecules that can be absorbed.

Question 18

When decaying waste plant material what is formed?

Answer 18

Compost - natural fertiliser.

Question 19

How is biogas made?

Answer 19

From decomposed plant material and animal waste by using large anaerobic fermenters that will break down waste material.

Question 20

Define biodiversity.

Answer 20

Variety of different species in an ecosystem.

Question 21

Are ecosystems with high biodiversity more or less stable and why?

Answer 21

They are more stable because they have reduced interdependence between organisms.

Question 22

Disadvantages of deforestation.

Answer 22

Less CO2 taken in,
More CO2 in the atmosphere
Less biodiversity

Question 23

What is the disadvantages of destroying peat bogs?

Answer 23

Adds more CO2 in the air.
Reduces habitats.
Peat being used faster than it can be formed.

Question 24

What are the consequences of global warming?

Answer 24

Ice melts sea levels rise causing flooding and loss of habitats.
Distribution of wild animal and plant species is changing.
Biodiversity could decrease if species are unable to survive.

Question 25

How can we maintain biodiversity and give examples?

Answer 25

Scientists have put together a program into place to try and reduce human impacts on biodiversity. Breeding programmes - endangered species. Protection and regeneration of rare habitats. Reintroduction of hedges and wildlife corridors on farmland. Recycling, reusing and reducing waste. Reducing deforestation.

Question 26

What are the trophic levels?

Answer 26

Producer - 1 Primary consumer - 2 Secondary consumer - 3 Tertiary consumer - 4

Question 27

Define biomass.

Answer 27

All the living material of an organism.

Question 28

What happens at each level?

Answer 28

Energy is lost at each level due to; glucose being used for respiration not all ingested material being absorbed some absorbed material is lost as waste/

Question 29

Roughly how much biomass is passed on at each trophic level?

Answer 29

10%

Question 30

Define food security.

Answer 30

Having enough food to feed a population.

Question 31

What are things that affect food security?

Answer 31

Environmental changes leading to droughts or flooding causing famine. The increasing cost of agriculture. New pests and pathogens damaging crops. Conflicts in some countries reduce access to food or water. Changing diets in developing countries.

Question 32

What are restrictions in place to prevent over fishing?

Answer 32

Fishing quotas Net size

Question 33

When growing crops what is usually done to increase yield and efficiency of energy?

Answer 33

Large fields of one species, no hedges = monoculture. Use of pesticides to reduce crop damage by insects. Use of herbicides to reduce weeds, reduces competition. Use of fertiliser to increase growth.

Question 34

When farming livestock what is usually done to increase yield and efficiency of energy?

Answer 34

High protein diet to increase growth. Antibiotics given to reduce pathogen infection Restrict movement to reduce energy loss. Keep warm indoors to reduce energy loss for maintaining body temperature.

Question 35

What are alternate methods to intense farming and what is the drawbacks?

Answer 35

Organic farming reduce the use of pesticide, herbicide and chemical fertiliser which reduces impact on biodiversity and the amount of pollution. Less yields.