Biodiversity

Question 1

what could differences between individuals of the same species be due to?

Answer 1

environmental or genetic factors, or a combination of both

Question 2

species

Answer 2

group of similar organisms which are able to interbreed to produce fertile offspring

Question 3

why do scientists take a sample of a population rather than looking at the whole thing?

Answer 3

to save time and resources

Question 4

importance of courtship behaviour

how does courtship behaviour work?

Answer 4

• to attract a mate of the same species (species recognition)
• prevent interbreeding between different species - as offspring won’t be fertile
  courtship behaviour is species specific, so only members of the same species will exhibit and respond to the same courtship behaviour.

Question 5

what is necessary before successful mating?

Answer 5

courtship behaviour

Question 6

how does a phylogenetic classification system arrange species?

Answer 6

into groups based on their evolutionary origins and relationships

Question 7

how is phylogenetic classification a hierarchy?

Answer 7

smaller groups are placed into larger groups and there is no overlap between groups.

Question 8

what is each group in phylogenetic classification called?

Answer 8

a taxon

Question 9

what are the taxa in phylogenetic classification?

Answer 9

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 10

what does a binomial consist of?

Answer 10

genus and species name

Question 11

what is the purpose of the binomial classification system?

Answer 11

to allow for universal identification of a species and avoid confusion with common names

Question 12

What is species richness?

Answer 12

a measure of the number of different species in a community

Question 13

what does the index of diversity describe?

Answer 13

the relationship between the number of species in a community and the number of individuals of each species

Question 14

equation for index of diversity

Answer 14

d = N(N-1) / E n(n-1)

Question 15

why is index of diversity a more useful measure of biodiversity that species richness?

Answer 15

as it takes into account the number of organisms of each species as well as the number of species. This is useful as some species may only be present in small numbers

Question 16

4 ways of comparing genetic diversity within or between species

Answer 16

• the frequency of measurable or observable characteristics
• the base sequence of DNA
• the base sequence of mRNA
• the amino acid sequence of the proteins encoded by DNA and
mRNA.

Question 17

how did genetic diversity used to be measured?

Answer 17

by comparing observable characteristics

Question 18

why is it important that sampling is done randomly?

Answer 18

• so that the sample is representative of the whole population
• to avoid bias

Question 19

standard deviation

Answer 19

a measure of the spread of values around the mean/variation in a sample

Question 20

standard deviation bars overlap

Answer 20

means the difference between samples is not significant.

Question 21

biodiversity

Answer 21

the variety of living organisms in an area

Question 22

agricultural techniques which can reduce biodiversity (4)

Answer 22

hedgerow/ pond/ woodland removal, pesticides, herbicides, monoculture

Question 23

How can hedgerow/pond/ woodland removal in agriculture reduce biodiversity?

Answer 23

reduces number of trees/ hedges/ habitat diversity, so species may lose shelter and food sources and die or have to move elsewhere.
Linking!!

Question 24

How can pesticides in agriculture reduce biodiversity?

Answer 24

pesticides = chemicals which kill species which feed on crops
Direct reduction in biodiversity as pest species are killed
species which feed on pests lose a food source so numbers could also decrease.

Question 25

How can herbicides in agriculture reduce biodiversity?

Answer 25

herbicides = chemicals which kill unwanted plants (weeds) | reduces plant diversity and could lead to reduction in numbers of organisms which feed on weeds.

Question 26

How can monoculture in agriculture reduce biodiversity?

Answer 26

monoculture = when fields have 1 type of crop only. Having a single plant type reduces plant diversity, habitat diversity so fewer other organisms are supported with habitat/ food sources

Question 27

Limitations of inferring genetic diversity by comparing the frequency of measureable/ observed characteristics (2)

Answer 27

- some characteristics are polygenic, meaning coded for by more than 1 gene and show continuous rather than discrete variation. this makes it hard to distinguish between different characteristics. - characteristics can be modified by the environments - so variation may be due to environmental rather than genetic differences.

Question 28

Why can comparing the frequency of observed characteristics be used as a measure of genetic diversity?

Answer 28

As observable differences between organisms are due to different alleles. A wide range of characteristics means there are many different alleles and high genetic diversity.

Question 29

How can comparing DNA base sequence be used to measure genetic diversity within a species?

Answer 29

- sequence DNA of members of the species - compare DNA base sequences between members - greater similarity means less genetic variation

Question 30

How/ why can comparing mRNA base sequence be used to measure genetic diversity?

Answer 30

mRNA is coded for by DNA - the mRNA base sequence is complementary to that of the template DNA strand. Variation in mRNA base sequence gives a measure of DNA/ genetic diversity.

Question 31

How/ why can comparing amino acid sequence of a particular protein be used to measure genetic diversity? drawback?

Answer 31

amino acid sequence of a protein is determined by mRNA base sequence and hence DNA base sequence. genetic diversity within and between species can be measured using the degree of similarity in the amino acid sequence for the same protein. however - genetic code is degenerate, so same amino acid sequence could be coded for by a different DNA sequence.

Question 32

use of courtship behaviour in classification

Answer 32

more closely related species have more similar courtship behaviour

Question 33

how can you ensure that variation observed in a sample isn't due to chance?

Answer 33

by performing a statistical test

Question 34

how can a balance between agriculture and conservation be achieved?

Answer 34

- protecting endangered species - planting new trees, making new hedgerows - making ponds - increases diversity as many species can survive here that can not on land - intercropping instead of monoculture - reducing pesticide and herbicide use

Question 35

why can comparing DNA base sequence be used to measure genetic diversity between species?

Answer 35

Species with more similar DNA base sequences are more closely related - have a more recent common ancestor. when 1 species gives rise to another, the DNA of the new and original species will initially be very similar. Mutations occur and the DNA base sequences gradually become more different.

Question 36

how are DNA changes linked to changes in the features of a species?

Answer 36

the DNA base sequence determines the amino acid sequence of an organism's proteins. Proteins determine features of an organism. This means changes is features are due to changes in the DNA.

Question 37

How can immunological comparisons be used to measure genetic diversity?

Answer 37

similar proteins bind to the same antibodies, for example antibodies for a human version of a protein will recognise similar proteins (similar tertiary structure) from other species. (=> similar AA, mRNA, DNA)

Question 38

How can courtship behaviour increase the probability of successful mating?

Answer 38

1. Recognise mate of same species; 2. Synchronises mating 3. Attraction of mate of the opposite sex; 4. Indication of fertility 5. Formation of a pair bond (to help raise young).