Ecology

Question 1

What is an ecosystem?

Answer 1

The interaction of a community of living organisms with the non-living parts of their environment.

Question 2

What is a community?

Answer 2

The populations of different species living in a habitat.

Question 3

What is interdependence?

Answer 3

How all organisms in an ecosystem depend on each other for food, protection and shelter to survive.

Question 4

What is biodiversity?

Answer 4

The variety of different species of organisms within an ecosystem.

Question 5

What do species depend on each other for?

Answer 5

• Food
• Shelter
• Pollination
• Seed dispersal

Question 6

What is a stable community?

Answer 6

When all the species and environmental factors are in balance so that population sizes stay constant.

Question 7

What are examples of stable communities?

Answer 7

Tropical rainforests and oak woodlands.

Question 8

What are the abiotic factors that can affect communities?

Answer 8

• Light intensity
• Temperature
• Moisture levels
• Soil pH and mineral content
• Wind intensity and direction
• CO2/O2 levels

Question 9

What are the biotic factors that can affect communities?

Answer 9

• Availability of food
• New predators
• New pathogens/diseases
• Species outcompeting each other

Question 10

What do the arrows in a food chain represent?

Answer 10

The movement of energy.

Question 11

Arrows move from … to …

Answer 11

PREY to PREDATOR

Question 12

Why does a self supporting ecosystem have to have an external source of energy?

Answer 12

Producers need sunlight for photosynthesis so that they can produce glucose to grow. The glucose serves as food for animals further up the food chain and the oxygen is needed for respiration by living animals.

Question 13

Why is it rare to have more than five trophic levels in an ecosystem?

Answer 13

There isn’t enough energy left as the energy moves up they food chain as it is lost through movement, growth, urine, faces and respiration.

Question 14

What is biomass and what shape does a pyramid of biomass look like?

Answer 14

The mass of living things.
It is pyramid shaped

Question 15

What are the two types of pyramid?

Answer 15

Pyramid of number and pyramid of biomass.

Question 16

What percentage of biomass is passed through each trophic level

Answer 16

10%

Question 17

Where is biomass lost?

Answer 17

• Energy, growth, movement
• Urine
• Faeces
• New organism
• Energy from cellular respiration is transferred by heating the surroundings

Question 18

What is a population?

Answer 18

A group of organisms of one species living in a habitat.

Question 19

Required Practical: How many plantain are there on Leebourne?

Answer 19

1. Measure the area of the field
2. Use a random number generator to choose a spot to place the quadrat
3. Count the number of plantain in the quadrat and repeat
4. Calculate an average and multiply the number of plantain in 1m^2 by the whole area.
   To get a representative and fair sample the quadrats need to be placed randomly and multiple times.

Question 20

Required Practical: How distance from a tree affects the light intensity and the number of plantain that can grow there

Answer 20

1. Place the transect line from the tree into the centre of the field.
2. Place a quadrat at regular intervals and use a light metre to measure the intensity and count how many plantain there are.
   To get a representative and fair sample place the quadrants at regular intervals and complete the experiment at the same time of day.

Question 21

What is an adaptation?

Answer 21

A characteristic of an organism that improves its chances of surviving/reproducing.

Question 22

What are the three types of adaptation?

Answer 22

• Structural
• Functional
• Behavioural

Question 23

What is the structural type of adaptation?

Answer 23

A feature of an organisms body that helps it survive/reproduce.
E.g. claws or spikes

Question 24

What is the functional type of adaptation?

Answer 24

A body process that helps an organism to survive/reproduce
E.g. making poison

Question 25

What is the behavioural type of adaptation?

Answer 25

Responses made by an organism that help it to survive E.g. hibernation

Question 26

What are the benefits of having a high surface area to volume:ratio?

Answer 26

You can lose heat faster which means animals in hot places are long and thin whilst organisms in cold environments need to conserve heat so have a lower surface area:volume area.

Question 27

What are extremophiles?

Answer 27

Organisms that live in very extreme environments such as high temperatures/pressure or high salt concentration.

Question 28

Why are animals in a food chain called consumers?

Answer 28

They get their food molecules by eating other organisms.

Question 29

Describe the carbon cycle.

Answer 29

- Carbon enters the atmosphere as carbon dioxide from respiration and combustion - Carbon dioxide is absorbed by producers to make carbohydrates in photosynthesis - Animals feed on plants, passing the carbon compounds along the food chain (most carbon they consume is exhaled as carbon dioxide during respiration) and the animals and plants eventually die - Dead organisms are eaten by decomposers and carbon in their bodies is returned to the atmosphere as carbon dioxide. In some conditions decomposition is blocked. The plant and animal material may then be available as fossil fuel in the future for combustion

Question 30

What does decay do?

Answer 30

Transfers carbon from dead materials to the atmosphere.

Question 31

How do plants benefit from the microorganisms in the carbon cycle?

Answer 31

Microorganisms release carbon dioxide and mineral ions for plants to re-use.

Question 32

Describe the water cycle.

Answer 32