4.2 Biodiversity

Question 1

What is a population of a species?

Answer 1

The total number of organisms of the same species in a habitat

Question 2

What is a species ?

Answer 2

A group of a specific organisms that can produce fertile offspring.

Question 3

What is a habitat ?

Answer 3

Where a population lives.

Question 4

Define communities

Answer 4

Different populations in the same habitat.

Question 5

Define ecosystem.

Answer 5

All of the biotic, abiotic and communities interacting in a habitat.

Question 6

Define species richness.

Answer 6

The number of different species in a particular area.

Question 7

Define species evenness.

Answer 7

The abundance of each species in a habitat.

Question 8

What is the formula for the simpsons index and how do you read it ?

Answer 8

•D = 1 - (Σ(n/N)^2)
•The value to any simpsons index equation will be between 0 and 1. The closer to 1 the answer the less diverse the population.

Question 9

Why is genetic diversity important ?

Answer 9

The risk of a new biotic change ie habitat change or new pathogen eradicating a species is amplified with narrow genetic diversity.

Question 10

How do you interpret data given from the spearman’s rank formula ?

Answer 10

•If the Rs value is greater than the critical value ( will be provided ) you support the null hypothesis, if not reject it.
•This is said with 95% accuracy.

Question 11

What is needed to begin when doing inferential statistics ?

Answer 11

A null hypothesis and two sets of data.

Question 12

What’re the advantages and disadvantages of random vs non random sampling ?

Answer 12

•Random sampling gives the fairest estimation of a whole population as it ignores bias
•Non random sampling can be used to determine change across a habitat

Question 13

What are some examples of random sampling methods?

Answer 13

•Quadrats are suitable for measuring populations of plant life and slow moving animals
•Sweeping nets, Pitfall traps (buried jar), Pooters (jar with two tubes to suck up insects), tullgren funnels and kick sampling ( kicking mud from a stream into a net ) can all be used to count insects and aquatic life.

Question 14

What are some examples of non random sampling ?

Answer 14

•Opportunistic sampling is when you pick what areas to sample based on its properties ie type of land
•Stratified sampling is when you base your sampling locations based off of the % coverage of an area. Eg if dark woodland covers 74% of an area then 74% of your samples will be there
•Systematic sampling involves measuring a change in something such as soil pH or light intensity using a transect.

Question 15

How can a populations have varying genetic diversities ?

Answer 15

There will be different numbers of polymorphic genes in each organisms DNA. More polymorphic genes means more alleles are present : essentially meaning there is greater change for different physical traits to be expressed in offspring.

Question 16

How can species evenness be measured? What does the answer mean for genetic diversity ?

Answer 16

•It can be calculated either by doing population / total number of organisms x100 or area occupied by one species / total area x100
•The more evenly distributed a habitats species are the more genetically diverse it is.

Question 17

A population in a zoo needs to have its genetic diversity assessed. How would a value be achieved ?

Answer 17

Calculating the proportion of polymorphic gene loci gives an idea of genetic diversity. Polymorphic gene loci / total gene loci x 100

Question 18

What are three factors caused by humans that negatively affect biodiversity?

Answer 18

•Human expansion causes more and more land to be occupied by housing and industry, removing habitats
•Monoculture in farming greatly reduces genetic diversity in habitats
• Climate change brings rapid change to habitats, which some species may not be able to survive leading to lower diversity.

Question 19

What are the ecological reasons to maintain biodiversity ?

Answer 19

•Ensuring no keystone species numbers diminish (maintaining species interdependence)

Question 20

What is an economic reason to maintain biodiversity?

Answer 20

Excessive monoculture results in the minerals in soil being depleted. Varying crops means that stable levels of each each mineral with remain

Question 21

What is an aesthetic reason to maintain biodiversity ?

Answer 21

To protect landscapes

Question 22

What is an in situ method of maintaining biodiversity?

Answer 22

•’On site conservation’
•Wildlife reserves and marine conservations are both in situ methods as they protect organisms in their natural habitats (preventing human damage)

Question 23

What is an ex situ method of maintaining biodiversity

Answer 23

•’Offsite conservation’
•Seedbanks and botanical gardens are both ex situ methods as they take organisms away from their natural habitat in order to ensure their safety.

Question 24

What does the Conservation on International Trade of Endangered Species (CITES) agreement entail ?

Answer 24

It has been signed by over 150 countries and allows the monitoring of international trade in order to prevent the exploitation of endangered species.

Question 25

What decisions were made at the Rio Convention of Biological Diversity ?

Answer 25

•To attempt to conserve habitats through various methods
•To use biological resources sustainably
•To fairly share the benefits of genetic resources

Question 26

What was the countryside stewardship scheme (CSS) ?

Answer 26

This scheme conceptualised in the 1980s financially rewarded landowners who encouraged biodiversity on their land.