classification and courtship Flashcards
(15 cards)
what are the problems with classification techniques
species aren’t fixed- can evolve
may be large variation between members of a species
many species are extinct and have no fossils
some species don’t produce sexually
isolated groups may be classed as separate species but may actually be able to interbreed
what are the taxonomic ranks
domain kingdom phylum class order family genus species
what must the genus always have what and what does it indicate
how must species be written
capital letter
same genus= same evolutionary origin ,share a common ancestor
species written in italic or underlined
what is a species
organisms that can reproduce to create fertile offspring
what are phylogenetic relationships
shows evolutionary groups within groups shows no overlap
what are phylogenetic trees
show evolutionary relationships
closely related animals have a common ancestor that diverged more recently
how to use protein structure to determine evolutionary relationships
look at amino acid sequences/primary structure
closer the amino acid sequence the closer the relationship
protein structure related to DNA base/triplet sequence
how to use mRNA or DNA base sequence to determine evolutionary relationships
more similar base sequences = closer relationship
also likely to have amino acid sequences in common
why is comparing base sequences from a gene better than amino acid sequences for which the gene codes
DNA code is degenerate so more than one code for some amino acids
introns are non coding
triplet code- more bases than amino acids
how does courtship behaviour increase the likelihood of successful mating
allows members of same species to recognise each other
stimulate release of gametes
allows individuals to recognise opposite gender
often an indication of fertility
help form a pair bond
what is biodiversity
the range and variety of genes species and habitats within a particular environment
link between more grasses and biodiversity
more habitats and greater variety of food sources often greater biodiversity
what is species diversity
genetic diversity
ecosystem diversity
species diversity = no of different species and the number of individuals of each within any community
genetic diversity= no of different alleles of each gene. may be low if there has been inbreeding or the pop started from only a small no of individuals
ecosystem diversity= range of different habitats within a particular ecosystem
what is species richness
the number of different species in a community
how does farming and biodiversity link
often reduces it - less hedgerows, monoculture, overgrazing of land, pesticides etc
conservation techniques can help to resotre it e.g crop rotation
