variety of life Flashcards
(19 cards)
endemic meaning
found in only one location
explain the effect of successful interbreeding on the genetic diversity of a species
increases genetic diversity/ size of gene pool
because it introduced new alleles into the population
state what is meant by the term allele
alternative/ different form/ version of a gene
describe what needs to be measured in order to compare the biodiversity of two rainforests
counting the number of different species
counting number of individual per species
discuss why number of species of animal may change in future (in restricted [number] of locations)
increase: fragmentation of habitat/ geographical isolation
different selection pressures on one species
different allele frequencies within separate popualtions
evolution leading to formation of new species
decrease: endangerment
only one population of a particular species
vulnerable to inbreeding depression
at risk of natural disaster/ disease/ predation
therefore may become extinct
discuss what information needs to be collected from two woodlands to make a decision about site of new building work
biodiversity measured using diversity index
species richness assessed
genetic diversity of populations/ species
presence of any endemic/ rare species
explain how the primary structure of an enzyme could be used to produce a phylogenetic tree
determine sequence of amino acids of enzyme
determine number of sims/ diffs in sequence of AA between species
greater number of diff= less closely related species
explain how two species couldve arisen from a common ancestor
mutation leads to variation within population of animal
natural selection led to those individuals having an advantageous allele- survived to reproduce
therefore giving rise to two populations with differing allele frequency
result of natural selection the populations became reproductively isolated
sympatric speciation
explain why two animals are now classed as different species
no longer able to interbreed to produce fertile offspring
because populations have become reproductively isolated
describe the features that could be used to identify prokaryotic cells in blood sample
presence of cell wall
circular DNA/ plasmids
small/ 70S ribosomes
pilli/ flagellum
capsule/ mesosome
describe how the hardy-weinberg equation can be used to provide evidence for the changes in an elephant population
calculate the allele frequencies/ number of dominant and recessive alleles in the population
regular sampling over a period of time
explain how molecular phylogeny can be used to show that two populations were reproductively isolated
comparing similarities and differences in dna/ proteins
compare nucleotide sequences/ amino acid sequences
the greater the number of differences, the more likely they are to be reproductively isolated
describe how mutations may lead to two populations becoming a separate species
mutations result in the production of new alleles
selection pressures cause the alleles to be advantageous
more individuals with the advantageous alleles survive and reproduce
after time, the population would not be able to reproduce with other badger species to produce fertile offspring
state what is meant by species richness
measures number of species in a habitat
state what is meant by heterozygosity index
measure of genetic diversity within a species/ population
state what is meant by the term species
a group of organisms that can interbreed to produce fertile offspring
explain why the frequency of a specific allele may change from one generation to the next
the allele may undergo mutation
gene flow may cause alleles to be lost or gained from population
due to natural selection/ change in selection pressure
because people with the recessive allele may not have children
explain how hardy weinberg can be used to show that natural selection is occurring in a population
shows the allele frequency in a population
if natural selection is occurring there would be a change in allele frequency over time
explain how molecular phylogeny could be used to determine relationships between subspecies of wildcat
compare sequences of bases of dna/ amino acids in proteins
the more similarities in common, the more closely-related the subspecies
