4.10 Biology - Biodiversity

species definition

species richness definition

• species → similar organisms that can interbreed and produce fertile and viable offspring

• species richness → different number of species in a community

genetic diversity definition

ecosystem diversity definition

• genetic diversity → variety of genes in a species in a community

• ecosystem diversity → variety of habitats

how does farming reduce biodiversity

• destruction of hedgerows

• selective breeding

• monocultures

• over grazing

• filling ponds / draining wetlands

solve ts

3.3

what is the binomial system

two name system - genus first name, species second name

why do species look similar

1. live in similar environment

2. similar selection pressure

3. similar alleles have selective advantage

4. similar proteins give similar characteristics

what is the classification system

• eight levels of taxa

• Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

what is a hierarchy

smaller groups arranged within larger groups with no overlaps

why do we need a system to organise species

• to keep track of changes

• so system is universal

what are more modern classification methods

• checking DNA, mRNA and amino acid sequences

what is phylogeny

• arranging species into groups based on evolutionary origins

• shows most recent common ancestors

why is courtship important

• allows to recognise members of same species

• allows to recognise opposite sex

• so their mate is strong and healthy

what are ethical & economical reasons to maintain biodiversity

ethical → prevent extinction , animal rights

economical → tourism, medical uses

index of biodiversity

measures relationship between number of species and number of individuals in species in a community

explain how a larger body size is an adaption to a colder climate

small SA:vol ratio

which reduces water loss

explain the principles biologists use to classify organisms into groups

• hierarchy - smaller groups are arranged within larger groups with no overlap

• phylogeny - species are arranged according to evolutionary origins and recent common ancestors are shown

• modern classification methods - DNA, mRNA and amino acid sequence

suggest how information on amino acids is used to construct a phylogenetic tree

those with similar sequences are more closely related

the greater the difference in amino acid sequences, the longer ago the groups diverged

Haemoglobins are chemically similar molecules found in many species.

Differences in the primary structure of haemoglobin molecules can provide evidence of phylogenetic (evolutionary) relationships between species.

Explain how

1. mutations change base

2. causing change in amino acid sequence

3. mutations build up over time