B7 - Ecology

Question 1

Describe what a habitat is
Describe what a population is

Answer 1

Place where an organism lives
All the organisms of one species living in one habitat

Question 2

Describe what a community is

Answer 2

populations of different species living in a habitat

Question 3

Describe what abiotic/biotic factors are

Answer 3

abiotic - non living factors of the environment
biotic - living factors of the environment

Question 4

Describe what an ecosystem is

Answer 4

interaction of a community with living organisms with non living parts of their evironment

Question 5

What do plants and animals compete for

Answer 5

Plants: light, space, water and mineral ions
Animals: space, food, water and mates

Question 6

What is interdependence

Answer 6

In a community, each species depend on other species for food, shelter, pollination, and seed dispersal and if one species is removed it can affect the whole community

Question 7

What is a stable community

Answer 7

In a community all species and environmental factors are in balance so that the population sizes aee roughly constant

Question 8

Give 7 examples of biotic factors

Answer 8

moisture level
light intensity
temperature
Carbon dioxide levels
Wind intensity and direction
Oxygen level
Soil PH and mineral content

Question 9

Describe how a decrease in mineral content could decrease a population size (4 marks)

Answer 9

A decrease in mineral content could cause nutrient deficiencies - could affect plant growth - causes a decrease in the population size

Question 10

Give 4 examples of biotic factors

Answer 10

New predators arriving
Competition
New pathogens
Availability of food

Question 11

Describe what a structural adaption is and explain how :
arctic fox
animals that live in cold places ( whales and arctic foxes)
animals that live in hot places (camels)
are adapted to their environment

Answer 11

features of an organism’s body structure - shape/colour
Arctic fox - white fur - camouflaged against the snow - avoid predators and sneak up on prey
Whales - thick layer of blubber - low sa:v ratio - retain heat
Camel - think layer of fat - large sa:v ratio - help lose heat

Question 12

Describe what behavioural adaptation is and give an example

Answer 12

Way an organism behaves
Many species (i.e. swallows) migrate to warmer climates during the winter to avoid problems living in cold conditions

Question 13

Describe what a functional adaptation is and give examples of how a :
desert animal
brown bear
are functionally adapted to their surroundings

Answer 13

Things that go on inside an organisms body that can be related to processes like: reproduction and metabolism
Desert animals conserve water by producing very little sweat and small amounts of concentrated urine
Brown bears hibernate over winter - lower their metabolism which conserves energy - don’t have to hunt when there’s not much food

Question 14

How is energy transferred through living organism

Answer 14

When organisms eat other organisms

Question 15

What are producers, primary consumers, secondary consumers, tertiary consumers

Answer 15

Producers - green plant/algae
Primary consumers - eat producers
Secondary consumer - eats primary consumer
Tertiary consumer - eats secondary consumer

Question 16

T/F
In a stable community containing prey and predators:
the population of any species is not limited by the amount of food available
If the population of the prey increases then population of predators decreases
If the population of predators increases, number of prey will decrease

Answer 16

population of any species is usually limited by the amount of food available
If the population of prey increases, population of predators increases
If the population of predators increases, the number of prey will decrease

Question 17

Describe the predator-prey cycle in relation to grass, rabbits and foxes

Answer 17

More grass - more rabbits
More rabbits - more foxes
More foxes - fewer rabbits
Eventually fewer rabbits will mean fewer foxes again
It takes a while for one population to respond to changes in the other population

Question 18

Describe how a quadrat could be used to investigate the number of organisms (6 marks)

Answer 18

Place tape measures along the length and width of the field to turn it into a large grid.
Use a random number generator to generate random coordinates.
Place quadrats at those coordinates and count how many dandelions are found in each.
Repeat at least 10 times
Calculate the mean number of dandelions per
Estimate total population : (area of field/area of quadrat) x mean number of organisms

Question 19

Describe how a transect could investigate distribution of organisms

Answer 19

Mark out a line in the area you want to study using a tape measure
Collect data along the line by using quadrats and moving the quadrats at set intervals i.e. 2 meters

Question 20

Describe the different stages of the water cycle (6 marks)

Answer 20

Thermal energy from the sun makes water from land and sea evaporate into water vapour
Water also evaporates from plants - transpiration
Water vapour rises - eventually condenses to form clouds
Water falls from the clouds as precipitation onto land
Water is absorbed by the soil and is taken up by plant roots - for photosynthesis
Animals produce faeces, urine and exhale -returning water to soil and atmosphere
Water that doesn’t get absorbed by the soil runs of into streams and rivers
Cycle repeats fr..

Question 21

Describe the different stages of the carbon cycle (6 marks)

Answer 21

CO2 removed from the atmosphere by green plants and algae during photosynthesis
Carbon is used to make glucose - which can be turned into carbohydrates, fats, and proteins
Plants and algae respire, some carbon is returned to the atmosphere as CO2
Plants/algae are eaten by animals, some carbon becomes part of the fats and proteins in their bodies. The carbon then moves through the food chain
Animals respire - some carbon is returned to the atmosphere as CO2
Plants, algae, and animals die - microorganisms feed on their remains
Combustion releases CO2 back into the air

Question 22

Which organism decompose dead organic matter

Answer 22

fungi
bacteria

Question 23

What is the name of the animal that feed on dead organic matter

Answer 23

detritus feeders
deepwoken guild ah name