TOPIC 4 - CH 10

Question 1

What is a species?

Answer 1

a group of organisms that are able to breed and produce fertile offspring

Question 2

Why is courtship behaviour essential?

Answer 2

For successful mating
and for recognising same species and opposite sex

mating behaviour synchronises to incidicate individualk is sexually mature and in season

Question 3

What do animals do in terms of courtship behaviour to ensure survival of the offspring?

Answer 3

• form a pair bond
• choose a strong and healthy mate

Question 4

What are the features of the binomial system (Linnaeus)?

Answer 4

• universal system based on latin/greek names
• first name is genus (generic name)
• second name is species (specific name)

Question 5

What is phylogenetic classification?

Answer 5

arranges species into groups according to their evolutionary origins and relationships

Question 6

What does phylogeny tell us?

Answer 6

which speciees are related and how closely related they are
all orgnaisms have evolved from shared common ancestors
this is shown on a phylogenetic tree

Question 7

What is meant by hierarchy?

Answer 7

when there are smaller groups arranged within larger groups
there is also no overlap between groups

Question 7

What is each group in a phylogenetic biological classification called?

Answer 7

Taxon

Question 8

How are individual classified according to taxonomy?

Answer 8

by their physical and biochemical similarities

Question 9

What is the order of the taxonomic ranks?

Answer 9

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 10

What are the 3 groups recognised in a domain?

Answer 10

Bacteria
Archaea
Eukarya

Question 11

What are bacteria?

Answer 11

group of single-celled prokaryotes
- no membrane-bound organelles
-unicellular
-smaller ribosomes (70s)
- cell walls made of murein
- single loop of DNA not associated with histones

Question 12

What are archaea?

Answer 12

single-celled prokaryotes
-genes more similar to eukaryotes than bacteria
- membranes contain fatty acid chains attached to glycerol by ether linkages
- no murein in cell walls
- complex form of RNA polymerase

Question 13

What are eukarya?

Answer 13

group of organisms made up of eukaryotic cells
- possess membranee-bound organelles
- membranes contain fatty acid chains attached to glycerol by ester linkages
- if they have cell wall no murein found
- larger ribosomes (80s)

Question 14

What are the four kingdoms that the Eukarya domain is divided into?

Answer 14

Protoctista
Fungi
Plantae
Animalia

Question 15

What does biodiversity refer to?

Answer 15

the number and variety of living organisms in a particular area

Question 16

What are the 3 components of biodiversity?

Answer 16

1. Species diversity - number of different species and number of individuals in each species within a community
2. Genetic diversity - variety of genes possessed by individuals in the population
3. Ecosystem diversity - range of different habitats

Question 17

What is species richness?

Answer 17

the number of different speciees present in a community

Question 18

What is index of diversity?

Answer 18

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

Question 19

How can farming reduce biodiversity?

Answer 19

• Remove habitats - hedgerow removal, draining wetlands
• using monocultures reducing species richness
• using pesticides and herbicides killing insects and unwated plants, reeducing food sources and habitats
  -overuse of fertilisers which can lead to eutrophication and damage aquatic ecosystems

Question 20

How can genetic diversity be assessed?

Answer 20

by comparing:
- frequency of measurable or observable characteristics
this may be less reliable as characteristics may also be influenced by the environment

• DNA base sequence

-mRNA base sequence
as it is transcribed from DNA

• amino acid sequence of proteins
  as it results from translation of mRNA and reflects genetic differences at functional level
  however genetic code is deegenerate

Question 21

What are the most accurate ways to measure genetic diversity

Answer 21

comparing base sequence of DNA and mRNA

Question 22

What are the step to investigate variation scientifically (5)?

Answer 22

• Data should be collected using random sampling to avoid bias
• take large samples to ensure results are representative of population
• A mean is calculated to summarise data
• Standard deviation calculated to show spread of values around the mean, which helps assess how much variation exists
• Statistics and standard deviation values can be used to interpret and compare whether the variation between differeent groups is significant

Question 23

Why is it more useful to calculate a species diversity index than just to record the number of species present?

Answer 23

it measures both the number of species and the number of individuals

therefore it take account of species that are only present in small numbers

Question 24

What are the 3 features of a phylogenetic system of classification?

Answer 24

1 - based on evolutionary relationships with organisms and ancestors 2- classifies species into groups using shared characteristics derived from ancestors 3- arranged in a hierarchy in which groups are contain within larger groups with no overlap

Question 25

Explain how agriculture has reduced species diversity

Answer 25

The few species possessing desirable qualities are selected for and bred other species are excluded by culling or using pesticides = many individuals of a few species = low species diversity

Question 26

Explain why there is a reduction in species diversity when a forest is replaced by grassland for grazing sheep or cattle

Answer 26

Forests havee many habitats with different species = high species diversity grasslands have a single later, feeewer habitats, fewer species = lower species diversity

Question 27

Suggest why the draining of ponds on agricultural land might have a greater effect on biodiversity than removing a hedgerow

Answer 27

Ponds have a habitat f or a wife range of aquatic species unlikelu to find alternative habitats Ponds may be a source of food and water for terrestrial specieas Hedgerow species are likely to have a larger range of alternative habitats with other sources of food and shelther so fewer species are likely to be lost

Question 28

What causes the DNA sequence of genes to change overtime?

Answer 28

mutations

Question 29

List 2 reasons why a sample may not be representat ive of the population as a whole

Answer 29

Sampling bias Chance variation

Question 30

Explain how sampling bias may be prevented

Answer 30

By using random sampling