Biodiversity

Question 1

What is biodiversity?

Answer 1

The variety of living organisms in an area

Question 2

What is a habitat?

Answer 2

The place where an organism lives

Question 3

What is a community?

Answer 3

A group of populations of different species living in the same area

Question 4

What is species richness?

Answer 4

The number of different species in a given area

Question 5

What is species evenness?

Answer 5

Number of individuals of each species

Question 6

What is a limitation of species richness?

Answer 6

It doesn’t take into account the number of individuals of each species

Question 7

Simpsons index of biodiversity?

Answer 7

Takes into account both species richness and evenness
Gives an idea of the number of each species relative to population size
Small and large populations are treated differently

Question 8

Reasons for maintaining biodiversity?

Answer 8

Moral and ethical
Ecological- increases the stability of ecosystems
Environmental
Economic- range of organisms contribute to medicine, ecotourism, science
Aesthetic- visual effects
Agricultural

Question 9

What are 2 direct impacts of farming?

Answer 9

Removal of hedgerows
Monoculture

Question 10

What does the removal of hedgerows do?

Answer 10

Increases the area of farmland by turning lots of small fields into fewer large fields
Destroys habitats- some species could lose their shelter and food source- species will die/ be forced to migrate

Question 11

What is monoculture?

Answer 11

Farmers have fields only containing one type of plant
A single type of plant reduces biodiversity and will support fewer organisms (as a habitat/food source) which further reduces biodiversity

Question 12

Indirect impacts of farming?

Answer 12

Pesticides
Escape of silage stores and slurry into water sources

Question 13

Pesticides?

Answer 13

Chemicals that kill pests that feed on crops
Reduces diversity by directly killing the pests
Any species that feed on the pests will lose a food source- their numbers could decrease too

Question 14

Escape of silage stores and slurry into water sources?

Answer 14

Pollution- decreases O2 levels

Question 15

How can biodiversity be increased?

Answer 15

Mature native trees- providing shade and shelter
Pond with varying depth
Species rich grassland
Hedgerows
Water trough

Question 16

Conservation measures for increasing opportunities for species diversity?

Answer 16

Biological control rather than pesticides
Crop rotations
Natural fertilisers
Reduced risk of eutrophication and slower release to reduce competition

Question 17

Conservation measures for increasing ecosystem diversity?

Answer 17

Replanting/maintaining hedgerows
Digging ponds
Producing hay from natural meadows (rather than grass)

Question 18

What is the definition of ecology?

Answer 18

The study of inter-relationships between organisms and their environments

Question 19

What is an ecosystem?

Answer 19

The living and non-living (abiotic and biotic) parts within an area

Question 20

Populations?

Answer 20

Group of individuals of one species

Question 21

Community?

Answer 21

Population of different species living and interacting in a particular place at the same time

Question 22

Habitat?

Answer 22

The place where an organism lives- characterised by physical conditions

Question 23

Ecological niche?

Answer 23

Describes how an organism fits within an environment
No 2 species can occupy the same niche (competitive exclusion principle)

Question 24

Microhabitat?

Answer 24

Part of a habitat e.g. mud at the bottom of a stream

Question 25

Biosphere/biomes?

Answer 25

A global ecosystem composed of living organisms and the non-living factors from which they derive energy and nutrients

Question 26

Abiotic/biotic factors?

Answer 26

Non-living (abiotic) and living (biotic) components of an ecosystem

Question 27

Biomass definition?

Answer 27

The total mass of living material in a specific area at a specific time

Question 28

Why is dry biomass more accurate than wet biomass?

Answer 28

Organisms contain different amounts of water in their tissues Dry biomass enables comparisons to be made between different organisms

Question 29

How would an organisms dry biomass be calculated?

Answer 29

Removing water from a specimen by heating in an oven at a low temperature to avoid burning Until the mass remains constant

Question 30

Define the term trophic level

Answer 30

A step in a food chain/food web Based on the feeding behaviour of an organism

Question 31

State 2 roles of nitrogen in living organisms

Answer 31

Nitrogen is used to build proteins Nitrogen is used to build nucleic acid e.g. RNA/DNA

Question 32

Describe the process of ammonification

Answer 32

Saprobionts/fungi convert the nitrogen- containing molecules found in dead organisms into ammonium compounds

Question 33

Define the term species diversity

Answer 33

The number of different species living in a habitat at a specific time

Question 34

Define the term saprobiont

Answer 34

Bacteria/fungi which carries out extracellular digestion by secreting digestive enzymes onto their food

Question 35

Why are decomposers essential to an ecosystem?

Answer 35

They release nutrients from dead or waste matter, making them available again to other organisms

Question 36

What is the habitat diversity of an area?

Answer 36

The number of smaller habitats available within it

Question 37

Compare species diversity with species richness

Answer 37

Both species richness and species diversity measure the number of different species in a community Species diversity takes into account the abundance of species, whereas species richness does not